Yeah would be a good idea .
If you haven't won after 5 turns with your mages some are rather useless
I saw it at the moment myself in one of my games : My 2 caelum mages were scripted to quickness + 4x false horror to scare away the enemy normal troops .
After the 5 scripted castings they prefered phantasmal warriors and i promptly lost the battle marginal . If they had continued the horror spamming i would have won .
So if a battle Lasts longer than 5 turns and you mainly rely on Battlemagic after 5 turns or 3 with quickness you have bad chances .