[Saxon]

Swarm is really nice at the start of combat and is instantly in effect whenever cast. It holds up lots of troops so you dominate when the ground troops clash or it stops missile fire or it stops spells. Or it holds troops longer so you can cast spells or hammer with missiles. Sure, the bugs get killed of in a round or three, but the impact is almost always felt in a positive way.

Howl takes a long time to do anything and, aside from the occasionally killing a commander or two, tends to be too diffuse to really effect the battle. The longer the battle the more it does, while Swarm tends to be all at once.

On another spell, Troll King’s Court does produce pricy to upkeep units, but they come with an earth mage who can buff their protection and hit the other army’s. I find the trolls are damn fine infantry who are very durable and effective, particularly when the commander casts appropriate buff spells on them. I put them on the front lines not to kill them off, but as first class infantry who I want to keep around.