Played a warrior too, but i didn't relay so heavy on spirit of rage. Probably my bad, but usually the battles ended by turn 3-4, never use soul drain a single time, not even black hole (so not taking the dmg xp bonus at all), my troop just inflict enough damage; target on the first round, and time back on the second one, give me a few losses at the end of battle, if none and i didn't care too much about them anyway. No doubt that u reached level 30, u made an heavy use of them
(which probably is the right strategy for warriors) I also liked to have high rage, to max out crits chances/dmg, so i was a little greedy on using rage demanding abilities.