Once again, fuck the crusading mechanic (see number of turns).
As soon as you can, buy lots of archery ranges and recruit a stack of marksmen. For me, a big stack of them does 10 times the damage of a similarly sized unit of hellknights and they're pretty cheap. Might have to choose 'sharpshooters' that Regill suggests during an upgrade meeting in Drezen to unlock them as units.
Make sure you get heal wounds on your generals ASAP. Try to get prayer as well. Also, the one that adds to unit cap.
All the 'trap' type abilities for generals seem crap.
Most of the direct damage abilities are rubbish, too.