A lot of people do not like the idea of adding randomness to Total Warhammer, there was a discussion regarding misfires a while back where the option of pressing a button to temporarily increase the damage of a unit at the cost of taking more damage to represent the Skaven's weaponry being more likely to misfire more. Having to activate abilities requires at least two clicks as you need to pick the units you want to use an ability and then another one to actually activate it, this would make the faction harder to play, the more mechanics like this the more difficult the faction would be.
Something like this was actually implemented for Greenskins, many people found the old Waaagh army mechanic to be annoying because it felt random, the new battle Waaagh ability requires the click of a button to activate, while on tabletop Greenskin squabbling and Waaaghing was random 5/6 of the time, with the exception of one turn where I believe it was guaranteed. There is no longer any random chance for things to go wrong for Greenskins, there is no more stupid Waaagh armies, there is only the possibility of the player using their Waaagh too early or too late. Is this a good thing? Should armies that were more random on TT (Greenskins, Skaven) have more active abilities to represent their randomness? Do you agree that more randomness is bad for the game?
I personally hate the stupid Brayherd Beastmen armies because it is another **** stacked on top of a weak faction, but I found Greenskins to be strong enough before their rework that it was no big deal when my Waaagh armies went and did something stupid and I found that to be a positive part of Greenskin gameplay and I think I might come to enjoy Brayherds more if Beastmen were overall stronger. I would also like misfire mechanics for blackpowder units and more wacky possibilities in the casting of magic spells. I do not think any factions should be much harder to play than any other, instead, difficulty should be regulated by difficulty sliders in single player, that also makes factions easier to balance for multiplayer because CA will not have to deal with the headache of a faction doing bad on ladder overall but being amazing in tournaments.