In my game Nimrook had all abilities he could learn, when i recruited him into my team he only had a few abilities (for some reason i was able to recruit him after the first league i played), early on i tried to involve as much members of my team in the action as possible, so everybody would level up at about the same rate, i also played quite a few exhibition matches to learn certain key techs, other than that i didnt go through too much trouble in teaching Nimrook his key techs