[Twan]

With magic...

Most big tramplers have very low MR so against mammoths/elephants use control spells (or rage, confusion etc). One revolted mammoth may make all the squad useless as the other units will attack him with their weak trunk attack. Paralyzation, slaying, blindness etc... are also good.

Against human units like knights who don't have an insane strength, earth meld can be used to stop them (they will be at range at the end of round one, so cast it fast), then chaff in attack cavalry can arrives before they kill valuable units.