What is the source of the Mages’ power?

Recently, I decided to play as the mages. Honestly, I was disappointed. I wouldn't say they have any particular strengths or anything that could be a key to victory, and then I remembered that I had heard many times that the Academy is a very strong faction, etc. So, I became curious, maybe I was just playing them wrong? Maybe I was using the wrong tactics, heroes, and so on. I would appreciate some help because I have a lot of questions. Starting with the hero. Which hero do you play as, what are his advantages, etc.? I have developed a tactic: I choose a hero, level up his Mentoring skill, etc. Then, when he levels up, I hire an Ogre or a Narghile and level up their Spell Lore skill. Next, I would like to hear your thoughts on creatures. Which ones do you build first? Which ones are best to upgrade early on? And finally, let's stop at Miniatures for now. I've heard many times that they are good, etc. But if you're playing on Veteran or Hero difficulty, there's always a shortage of resources. And spending them on Miniatures instead of upgrading a creature? Besides, you can only make decent Miniatures towards the end of the game, when they don't play a big role anymore...