Greenskins need dlc to fill gaps in their roster, and could get 1 cool mechanic as flc. They need some units, without which they will become just worse ogre faction (aka little, **** ogres). The units would be useful but mostly reskins so not much effort and thanks to that the other part of dlc could get cool models and animations for monsters and for example nurgle chaos chosen.
LL Morglum Necksnapper https://warhammerfantasy.fandom.com/wiki/Morglum_Necksnapper
(can have several mounts).
Lord Black Orc Warboss (better duelist than regular orc, so just average Grimgor)
- savage orcs with Big Stabba https://www.reddit.com/r/totalwar/comments/7l5yu1/random_obscure_thing_i_really_want_but_will/
anti large, armour piercing, def against charge, melee weapon team, and traits typical for savage orcs
- spear chucka - reskinned dwarf ballista, anti large artillery https://warhammerfantasy.fandom.com/wiki/Goblin_Spear_Chukkas
- black orcs with silver shields
- big uns with bronze shields
- orcs with spears and shields
FLC new greenskin feature - spore infestation (corruption), based on lore. Greenskin buildings (maybe recruitment ones) and armies presence in any area should accumulate spore infestation. Also winning and even losing battles should accumulate big ammount of infestation.
The infestation should increase replenishment, growth, and decrease recruitment cost.
The most important, it should start rebellions for enemy factions, but not like all other corruptions, slowly reducing public order. Instead there should be a percentage chance, based on level of infestation, every turn to start a rebellion.
For example a greenskin faction has a settlement Barak Var and had accumulated 40% of infestation, when it was attacked and occupied by a dwarf faction. Infestation starts declining like other corrupiton but in the next turn there is, let's say, 39% infestation and 39% chance of immediate rebellion with full 20 unit army. If rebellion is destroyed infestation falls to 0%.
Winning and losing battles should give big, immediate bonus to infestation, based on units killed.
Units taking part in rebellion should depend on level of infestation. For example: infestation to 20% units are 1 tier, infestation to 40% units are 1 and 2 tier, infestation 100% units of all tiers.
So for example, a greenskin army has 1 settlement in a province, and accumulated 20% of infestation. It wins a battle and infestation jumps to 60%. There is now 60% chance of rebellion in an enemy province.