It will reduce diversity even more. As is, fire magic is the most used one, with air r90. With this, you will simply have ray, r50, r90, and the school will not matter whatsoever. Better to add in more unique spells, give some r90s more speed, some knockbacks or partial blinds, some heavier non-health stat drains and so on, so you can mix and match and choose depending on the situation, instead of blindly going 'My #1 in rotation r90 went off cooldown, cast it again' Think of it, what is water magic r90, for instance, applied a weaker slow melee and slow ranged, in exchange for doing reduced damage, would no one use it? Buff up underused spells, mayhaps nerf overused ones, but do not reduce diversity and choices. Instead, add more diversity and choices and strategy to the combat.