I generally ambush with half my ungor raiders and have 10 (2 units) left just hanging about, with nothing significant to do. Today I got a couple of small games in and found this cool trick:
Place ungor raiders on a 30-40 degree line in front of your heavy hitting gor/bestigor unit. This way if a unit charges they align to that angle, over run a bit, and then get flank charged (due to the original angle) by your battle force.

I'm still quite noob, but I just thought I'd share this with you fellow beastmen generals who are just getting into the game.