How to play against Wizards?

HE'S ARGUING WITH THE GREAT NECROMANCER AGAIN!

The Outcasts have a very small map.

It only seems small to you because the red faction can reach the blue faction in a few days. But in reality, the map profile states that it is a "small map with a Dungeon."

Gremlins and mages are immediately wiped out.

I can't quite picture that. Okay, you took an Ice Elemental, a Ring of the Elements, fine. You visited the Fountain of Magic, and you have, say, 60-70 mana. You eliminate the mages and gremlins. By this time, the mage will easily eliminate all your skeletons and zombies because he has the Wizard's Sign and much more mana. Plus, golems and gargoyles. If it's Hafiz, then it's even worse. And summoning with the Pain Lord is great; with this build, I can easily rush Kaspar with the Outcasts and defeat anyone.

The opponent won't have time to summon Titans.

What Titans? Have you even played as a hero at all?

Added 7 minutes later

There is AI behavior for the hero, where the computer can become aggressive towards exposed units, even if there are other available troops to eliminate them at the moment.

That doesn't happen at all.