The eternal question: which heroes are better, mages or warriors?

Battle mages are awesome. Sometimes, the battle hasn't even started, and magic has already decided everything. But here's the downside: not all spells can fit in a spellbook. I was playing through the Dragon Slayer campaign, and I only succeeded because of the "Explosion" spell. I went to a town, learned "Slow," and then "Explosion" disappeared from my spellbook. :( (Maybe someone knows where to find the removed spells:smile45:)