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

I used to choose mages, but now I prefer warriors as my main commander. Mages are often burdened with various minor and useless secondary skills (mysticism, learning, intelligence, keenness), and they don't always get the necessary ones (logistics, ballistics).
However, it's easier to start with a mage. A mage can be better as a garrison commander: they will attack the besiegers with spells for longer and more effectively while their monsters are behind the walls. In addition, mages are preferable in the Snow and perhaps in the Dungeon towns.