Start on "Hero".

Well, mages are one of those factions that aren't too difficult to start with. Mana doesn't run out as quickly as it does for Warlocks. It's best to build mage guilds as quickly as possible, because the strength of mages lies more in the hero than in the troops. You can improve the summoning skill there, and you can definitely win. You can also choose a second school. Footmen work well with mines if they appear. Eliminate archers using the Sign of the Magician, and before that, quickly block them with some level 1 gargoyles. If you have a Crystal of Secrecy or a Wall of Swords, it's even easier.
In general, you have to look at the situation. It depends on who you're playing as and against, and what spells you have. Heroes depend heavily on random events.

If you're having trouble, I would just suggest that the author of the topic start with a simpler option. Even with Hafiz. Orks are often chosen because of their specialty, but people have noted more than once that the developers gave her too small values in the specialization, so it almost doesn't work in practice. Hafiz's specialty does work. + a bunch of gremlins and a ballista at the start. A strong hero, can even play in the late game, the main thing is to start quickly without any problems. Another option is Razaz. I wouldn't choose the others at the beginning, although you can later, if the game is going well for you.

The one who uses fireballs is very good for a quick start on small maps. Especially if the Phoenix Feather Cloak is somewhere nearby. And a well is definitely not superfluous. And ideally, Hafiz should be bought in the tavern in the first few weeks and used as a secondary hero.