There's no reason to have everybody in one unit wielding what amounts to basically a clone of the same weapon anymore. We're talking about a culture here where very few weapons were really "standard". The battlefield was a surprisingly colorful, varied and sometimes.. weird place. There were so many interesting spear types, types of naginata, types of bows, etc... Really, I'd like to go into a little detail about each of these.
-Bows (yumi): Bows were usually daikyu (longbow), but sometimes hankyu (shortbow) size. They came in various colors and styles, from the more natural looking ones to heavily lacquered. The construction of bows in this era was similar to today, but with fewer laminations. More laminations and stronger bows with greater range and power should be a researchable tech. Fire arrows and whistling arrows should not
, as they were already commonly known and had limited uses (which would add a certain layer of strategy without making them overpowered and simply silly). The whistling arrows were used as a signal to start a battle, and fire arrows were used to... set fires. Not kill people.
-Spears (yari): Loads of variations. Some yari were very complex. For example, some polishers still refuse to polish jumonji (cross shaped) yari just because of the complexity (having to basically shape stones specially suited to the job - stones that can be rather expensive). Each of these spear types had different quirks, but most basically worked the same (with some exceptions which we need not get into - see capture weapons). Various lengths... Some yari were extremely short, others were pike length. Longer spears and more complex types should be some sort of researchable tech.
-Glaives (naginata): Some variations here as well. Some naginata were rather large and beefy. Some were exceptionally so -- the onaginata ("big naginata", self explanatory) was particularly heavy and thick. Some naginata had parrying hooks and the like (kagitsuki naginata). Some were even straight bladed, much like a single edged yari... I mean, there's so many ways to depict these polearms. Various lengths at the haft, with some being rather short (nagamaki) and some being exceptionally long (I forget the name of these, but there are some insanely long naginata out there). Parrying hooks and crossbars and the like = researchable tech.
-Great swords, long swords and short swords (nihontou): Fewer variations in the shape and style, but far more variations in the wearing and aesthetics. Swords in this era tended to be longer, beefier and rather more curvy. Some were straighter and shorter, however. Variations here could be the different types of curvature, different colored mountings, whether or not the blade is worn in the obi or slung from it like a tachi, or maybe something in between (handachi). Some swords were actually mounted to be wielded one handed. Maybe longer blades like nodachi, which required more skill to make, could be researchable tech.
-Guns (teppou): Guns had some variations too. Some were quite large, more akin to a hand-held cannon. Others were rather smaller. Some had primitive sights of hanging rope, some others had a primitive bipod to steady the weapon. Nicer weapons, waterproofing (suggested by a previous poster), etc = researchable tech.
-Throwing weapons (touteki buki): The throwing of stones was, as I've mentioned before, very common. Uchine, or throwing spears, weren't quite as common but were indeed used at times. Nageya, or throwing arrows, also existed and were used. These were not precursor weapons like those used by other cultures... These were spur of the moment sorts of things used to distract and possibly wound an enemy in order to close the distance. Throwing spikes (bo shuriken) and throwing stars (hira shuriken) did NOT exist yet.
-Capturing tools (torimono dougu): Weapons like kabutowari, sodegarami and some forms of tsukinari yari. These were used to capture and trap prisoners or otherwise drag people to the ground. They could easily be mixed in with spear units, etc. There are a lot of these. If you absolutely must incorporate war dogs, arm their handlers with these and make their purpose at least similar to what they would have done IRL... Hunting down and capturing routers, not fighting on the battlefield. These could be researchable tech, along with (/gag) the dogs. Please refrain from dogs in armor, though.
-Armour (yoroi): Lots of different types and such, some more complex than others. When trade with Europeans starts, some of the higher, better paid samurai should have European style breastplates and the like. It was very much in vogue, but very rare due to the expense of acquiring such a piece. Stronger armors should be a researchable tech.
If this game is truly about simplicity, why not focus on some of the little things? I personally think that there should be a simulated element of "personal preference" here. Here's how I see implementation:
It's simple - two things should control the quality of armor and weapons. First, how much you're paying a unit would influence how much they spend on weaponry. Second, access to craftsmen - skilled craftsmen can make better weapons, faster. The five craftsmen that should be represented are bowyer, polisher, bladesmith, gunsmith and armorsmith. The various levels of bowyer and gunsmith would make better projectile weapons. Increasing levels of bladesmiths would make stronger blades, while polishers would allow more complex designs with defense and parrying bonuses in some cases. Armorsmiths make increasingly better armor.
The way I see it, equipment is doled out automatically. Hands-off. How much you pay a unit depends on their experience and how much money you're allocating to military expenditure overall. As they get more experienced they "level up", so to speak, and become slightly more expensive to keep. Armor colors and styles and such would depend on the faction, the unit type/tier and their home region. When you add new recruits to an old unit, they should get a slight experience bonus but should be paid less than the guys originally in the unit. The more experienced guys should still be in the mix, and should be better armed and equipped and the new guys equipped according to their own experience rather than the entire unit being nerfed.
Maybe there could be five levels within a unit, with upgrades happening WITHIN said unit. Samurai with short spears tended to fight AMONG levies with pikes rather than separately, so I see them being mixed together. Since there was no clear line between "samurai" and "peasant", I made the following list as such. The mounted warriors are different because they tended to be landed, stipended, usually hereditary samurai.
-levy archer - cheap bows, minimal armor, short swords, poor morale
-experienced levy archer - cheap bows, jingasa and domaru, short swords, fair morale
-professional archer - middling bows, middling armor, some jingasa, swords, good morale
-elite archer - good bows, good armor, good swords, excellent morale
-archery marksman (hero) - excellent bows, excellent armor, excellent swords, increases morale
-levy gunner - cheap guns, minimal armor, short swords, poor morale
-experienced levy gunner - cheap guns, jingasa and domaru, short swords, fair morale
-professional gunner - middling guns, middling armor, some jingasa, swords, good morale
-elite gunner - good guns, good armor, high grade swords, excellent morale
-gunnery marksman (hero) - excellent guns, excellent armor, excellent swords, increases morale
-emergency levy - bamboo spears or farm tools, mostly unarmored, instantly recruitable, some short swords, poor morale
-levy warrior - long spears, domaru and some jingasa, short swords, fair morale
-country warrior - long spears, regular spears or naginata, middling armor, some jingasa, swords, good morale
-professional warrior - good spears, nodachi or naginata, good armor, good swords, excellent morale
-kensei (hero) - excellent spears, nodachi or naginata, excellent armor, excellent sword, increases morale
-levy patrolman - sticks, rope, minimal armor, short swords, poor morale
-experienced levy patrolman - sticks and simple capturing tools, rope, jingasa and domaru, short swords, fair morale
-professional patrolman - simple capturing tools, rope, middling armor, some jingasa, swords, good morale
-elite patrolman - dogs, complex capturing tools, rope, good armor, high grade swords, excellent morale
-master patrolman (hero) - high quality dogs, excellent capturing tools, rope, excellent armor, excellent swords, increases morale
-mounted page - horses, cheap spears, cheap armor, cheap swords, poor morale
-mounted spearman - middling horses, middling spears, middling armor, middling swords, fair morale
-veteran mounted spearman - middling armored horses, good spears, good armor, good swords, good morale
-elite mounted spearman - good armored horses, good spears or naginata, good armor, good swords, excellent morale
-mounted kensei (hero) - excellent armored horses, excellent spear, naginata or nodachi, excellent sword, increases morale
-mounted archer - horses, cheap bows, cheap armor, swords, poor morale
-experienced mounted archer - middling horses, middling bows, middling armor, middling swords, fair morale
-veteran mounted archer - middling armored horses, good bows, good armor, good swords, good morale
-elite mounted archer - good armored horses, good bows, good armor, good swords, excellent morale
-mounted archery marksman (hero) - excellent armored horses, excellent bows, excellent armor, excellent swords, increases morale
-recruit infantry - cheap spears, sticks or farm tools, mostly unarmored, some swords and short swords, poor morale, fights dirty
-regular infantry - spears, sticks, capture tools, some domaru and jingasa, some swords, fair morale, fights dirty
-strongman infantry - axes, spears, naginata, mallets, domaru or cheap stolen samurai armor, some swords, good morale, fights dirty
-mounted bandits - horses, spears, naginata, nodachi, mallets and maces, pilfered samurai armor, swords, excellent morale, fights dirty
-elite mounted bandits (hero) - good horses, various heavy weapons, throwing weapons, pilfered samurai armor, excellent swords, increases morale, fights dirty
-recruit skirmishers - cheap bows, minimal armor, some short swords, poor morale, fights dirty
-regular skirmishers - cheap bows, jingasa and domaru, some short swords, fair morale, fights dirty
-veteran skirmishers - bows and guns where available, pilfered armor, some jingasa, short swords and swords, good morale, fights dirty
-elite skirmisher - middling bows and guns where available, jingasa and domaru, good swords, excellent morale, fights dirty
-bandit marksman (hero) - excellent guns and bows, throwing weapons, pilfered armor, excellent swords, increases morale, fights dirty
Each year, a certain number of the middle classes of these should come of age for recruitment depending on what provinces you own and what kind of warrior they're known for. Recruitment should be simplified - hereditary samurai were trained by their family or sought training under a local warrior. They were not trained by the local government. Guns are an exception - the number of professional gunners available in a turn should be based on some sort of research in the tech tree and the number of guns available, as there is no hereditary tradition tied to them yet.
Also, there should be attrition involved with certain weapons and unit types. Spears and naginata should have a small chance of breaking, rather than spearmen simply drawing swords when an enemy gets too close. Bowstrings should have a small chance of snapping, forcing a bowman to change strings. Guns should have a small chance of exploding and killing the less experienced gunners. Horses should have a small chance of getting killed in a melee. Horsemen, too... There should basically be horses galloping off the field, confused.
Weapons aside, I think the way units work together could also be improved. Say, you have one unit of archers, one unit of spearmen. You should be able to put the archers out front, click on the spearmen, and then right click on the archers to tell the spearmen to defend the archers if anybody gets too close. Then, you should be able to do the same with the archers... There was a tactic in this era where archers would fight with the spear formations of the time, crouching and shooting. http://www.youtube.com/watch?v=QhJotVk7nGk
Likewise, it was common for horsemen to fight in mixed formation with spearmen. I think any unit should be able to work with any other unit with a simple click. Maybe call it a combination formation or something. Also, I'd like to see actual Japanese formations, which can be changed via a mini menu in mid battle. Moving formations like the wheel or the crane would be really interesting.
What I'm asking is to bring the chaos of combat to the Total War series without necessarily having to add a whole bunch of blood and gore, and screw up the rating. It's too pretty the way it is right now. Shogun was amazing because it was something we had never seen before... Why not make Shogun 2 similarly groundbreaking? After all, so much has been done trying to bring detail to the battlefield itself... So, why not the soldiers and armies themselves? Discuss.
[EDIT] BTW, for dismounting... The way I think it should happen is you click on a unit of regular footmen, and then click on the horsemen. The lower ranked of them would protect the horses at the back of the formation and the horses would be attached to that unit. This is how it worked in reality.