Since I usually play on smaller maps, I prefer Warriors. A spellbook wouldn't hurt them, though. On larger maps, magic is, of course, good, but not on smaller ones. A Warrior's skills are always with him; a not-so-developed Sorcerer is enough to help him. But a Mage without strong spells is weak. For this, he needs a lot of resources to build Guilds, then visit them all (instead of fighting), and then there still might not be the necessary spells... By the time you can develop a more or less strong Mage, you're already finishing the game with a Warrior.