Haven buildings.

But golems are still better! What can mages do in melee combat when the enemy reaches them!

Mages manage to do their thing, but golems aren't always effective :( They may be faster than dwarves, but they still slow down. And you can control mages from the start :)
*I say this because I don't like using various speed boosts and wasting an entire turn on a hero, which, in my opinion, could be spent on more effective things ;) I only use speed boosts when the hero is very weak and can't do anything else :rolleyes:

Besides, if you think about it that way, you can immediately get rid of all arch