[Micah]

If you're playing SP then you're most certainly not playing the same game as all of us =)

It also depends what nation you're playing as. Troop-stomping is a pretty good strategy for Ulm, since the AI isn't going to be taking advantage of the appropriate counters (rust mist, iron bane, destruction, mind burn, lighting, magma eruption, etc.)

Magic is most often used as a counter-strategy for what your opponent is doing, so that your troops can win the battles. If you're facing hordes of enemy crossbows casting arrow fend and/or storm will render them near-useless. If you're facing down 100 barded elephants you're going to be happy to have 25 astral mages casting soul slay on them, or someone to cast flaming arrows on your legions of archers that would normally fail to pierce the protection value on the elephants, since even most heavy cav won't be able to do enough damage to the elephants before they get squashed.

The AI doesn't employ strategy, they don't mass specific troop types very effectively, and their mages rarely do anything of note, hence your own use of magic will generally be used more for artillery than it will be for saving your bacon against something your troops can't hack it against. I agree that some of the lower-level magic is pretty worthless, I'm on turn 15 of one game where I started an early war and I've done virtually no research, and it hasn't impacted me, but I'm getting ready to hit the books hard, because I'll lose out bigtime in the mid-game if I don't get competitive in the magic race very soon.