The worst thing is, you don't have any choices or differences in fight
Example Barbarian:
Let's imagine the damage dealt is 5, so:
Slash: Damage: 5
Roar: needs 4 rounds: Damage: 0+3*1.2*5=18 (4 x Slash = 20)
Headbutt: Half damage done, half received. I never had an opponent, which dealt more damage than me but i gave up at stage 100. Until then it has been absolutely useless.
Stab: Average Damage with 40% Armor: 0.65*5*1.4=4.75 (Slash=5)
Strike: Damage: 5+?
Charge: Damage: 0+2*5=10 (2 x Slash = 10)
So why won't you ever use anything different than strike? You have to be more precise in your calculations. If you have to wait some rounds for the dealt damage, this has to be an advantage.