I will be ranking these in order of significance by giving them an impact rating from 0 to 5 (0 - least important, 5 - highly important).
General Lack of Balance - Across almost all games, there are always factions, a faction, or paid DLC factions, that feature slight or major lacks of balance. However, it is given a low rating, because the units that usually are overpowered are not always spammed, can be limited, and can sometimes be countered in some way.
Various examples across 'free' games I have acquired and played of Total War:
Rome II - Rome is overpowered, pikes are powerful, barbarians are just weaker and more expensive.
Atilla - Rome II with new factions, units, cavalry added, with insanely large 'charge bonuses'. Cavalry Archers.
Empire - Very boring, added gunpowder units, did not really play it.
WarHammer/II - At least a few unit abilities and unique things have been added on, but still unbalanced regardless of a small step up the long ladder of needed improvements.
This means the game is not really a game, and you might as well play a card game where a few cards are simply 'better' in every way and then gamble on the output. Balance is not determined at all by the devs, usually players (who cannot be trusted to do any sort of balance) are put in charge of balancing a game to make the outcome less clear and the result less obvious.
Overall Impact Rating: 2 Slight Impact
Lack of Gameplay Abilities - Most of the battle is already decided by the time you pick your army. Even if a real countering RTS or skill related system were ever added to the game, it would still be decided by how many counters and the 'game of cards' you play in the army selection screen. In the actual battles, it is always just a unit-stats blob and the best/cheaper units win, with no skill involved.
Explanation: Due to this, many gaymers (some adults, some kids, some just seemingly braindead) opt to play defender sieges where they gain all the advantages possible ontop of their walls and other defenses, and then sit there trying to cheat by arranging a more massive victory for themselves before the game starts. For example, in a siege, a host who believes he is "pro" or "experienced" will do a ton of instantly obvious and fake things that take about 1 second to recognize, ranging from:
-asking no one to press ready, because he is slow, needs to set up all his extra traps, arrange his siege, place his pikes into unflankable streets, etc..,
-requesting that no one spams siege weapons because they mightbe the only thing that causes the defender to actually click their mouse button once or twice
-packing units into the unbalanced '2nd fort' in the center of a town to have free towers (that fire unlimited artillery), archers elevated that cannot be out-ranged, and pikes/heavy units simply unflankable, so that the very few options available to attack are now diminished or nothing.
I should not have to explain further how 'dumb' hosts who think they are superior simply by pre-arranging a win by unit selection and defense selections, and don't set up a fair and fun game is a big part of total war. It is not 'skill' or 'intellect' but rather stupidity packaged into a box for non clever people to use. The personalities of these types are usually blatantly cheaters or they are just like "XD!! Let's all be fair! xD!! - picks about 5 things that stack to their advantage that the attacker cannot do".
Overall Impact Rating: 4 Larger Impact
Multiplayer Lag - After waiting, following a host's rules, investing all the time setting up, there's always one pakistan man who lags up the lobby. Players seem to be very 'stupid' in determining, and overall how the whole sync/lag problem occurs.
Explanation: Very rarely is a player's computer experiencing enough frame-drop, or actual on screen lag to cause this. Most of the time, there's a high chance of at least 1 player joining and having a higher ping. Being p2p, this means the whole game will slow down to synchronize and compensate for this player's location or bad internet, so a player with 300 ping has a lot more impact than a 'server to client' game connection where lag usually only effects the lagging player. Also, there has NEVER been any dev even acknowledging the need for showing individual pings, bars, or anything, so thus the 'gamble' of starting a laggy game that will be unplayable and unfinished results in a big waste of time. Games become literally nothing more than a waste of time, they fail to complete, and this can all be caused by one high ping player who simply lives far away, and a combination of how the bad P2P engine handles it, not as the dumb community members claim is "BECAUSE ITS A 3v3, LOTS OF UNITS!".. As an ultimate result, even with a lack of understanding why the engine lags, and why it probably is lagging too much to play in a game, hosts cannot even identify and kick laggers or simply foreigners from their lobby to avoid wasting time after setting up the lobby, rules, and other parts of a battle.
Overall Impact Rating: 5 HUGE Impact
Recycled Iterations - because the community is full of braindead lord of the ring fans, kids, and other braindead individuals, they are more than willing to invest the 70$ or more in the 'newest' game (sometimes even invest in 10 to 20$ DLCs later too ) rather than protest and/or not buy it. The next game is usually just a slight change in graphics, swapping out of trees, textures, faction names, units, and mixing up of the 'stats page' of each type of unit for each faction. Sometimes, they will add a handful (yes, maybe like 2 or 3 things) of 'new things' to a game pertaining to MOBA abilities of units, general abilities, and other changes, but overall, even a glance at the campaign map shows that it is the same engine with different textures, banners, and a boring swap of the same old thing.
Explanation: Due to TW making profit from over-priced games and DLCs, it does not have to listen, fix bugs, or make a good game. For example, when Rome II came out, even after years of updates, there were times when the game just exits/crashes with no explanation whatsoever.. it was 'fixed' only after about 5 to 6years later. The idea of adding a buggy co-op campaign map is a result of over 15 years of requests that they turn the campaign map into a sort of RTS game where you can have invasions/players/other interactions with 'non-stupid-AI' (which they also fail to ever update so long as it can just play a battle or move things around). Of course these requests were not only ignored, but the want for a sort of PvP campaign map that lacks bugs has been pretty much thrown under the rug or a total failure on their part to deliver.
Overall Impact Rating: 3 Notable Impact (on decision to actually buy and play game)
Generally Brainwashed TW Players - there is not much to say in this regard other than, in combination with a few of the factors above, and so long as these individuals continue to pay TW in full for their latest games, DLCS, and other so-called "games" or "content", the same community will be catered to and the games will remain in an unplayable and time-waster state for all eternity.
Explanation: If a player doesn't acknowledge that the points here are all valid and have an effect, they are probably just going to result to mudslinging and namecalling because they are basically being told that their idea of being good at something is based on pre-determined and non-skill based type of games, something they will likely not take very well. I am surprised at the general lack of 'everything' in these games from balance, lag compensation, features, lack of bugs, and large price tags.
Overall Impact Rating: 4 Larger Impact
If anyone would like to expand on this or discuss it, feel free!