Rigth now generals even more matter then befor. You just need to undestand how. High martial define how good choice of tacktic general will have. Correct tactic can give 200-300% bonuses to some trops, or penalties to other. Bad general = your best trops lickly to have penalties in battle.IN many cases correct tacktics define win or lost. In addition moral, speed, terran, defnce traits have big influence on battle.
Right now generals have Mach bigger effects then befor.
Good choice of generals can let you win battle with half of army.