Newbie question: Best army buff paths/schools?

[Micah]

Ah, my mistake, normal Hirdmen, not Helhirdings. That's much better, although he shouldn't be using battleaxe infantry regardless, flails or morningstars are the way to go against hige defense.

Destruction is amazingly good. You might need more than one guy casting it so it'll get good coverage, but it's a fantastic spell. It's about 5 times as effective as strength of giants in terms of extra damage done in your example, so even with only 50% coverage you're still way, way ahead. The friendly fire potential is annoying, true, but your troops are much less likely to get hit than your enemy's troops (and if your guys do take a hit, even with armor they still have a really high chance of dying from a battleaxe Abysian)