Ideas and suggestions.

I suggest adding control abilities to other schools of fire magic: * Add movement point regeneration to water magic = logistics become even more valuable. * Add army stack teleportation from hero to hero to fire magic = weaker heroes can assist in clearing areas more effectively, intelligence becomes more important, and playing with multiple heroes becomes necessary. I suggest weakening the effect of the red spell: instead of completely disabling magic, it significantly reduces spell power (from -13 to -20) + reduces magic skill (from expert to advanced, from advanced to basic, basic removes the skill).