In the editor, there are only heroes of one class. We launch the game and observe... :D Then - yes, if there is no other choice, the tavern will only have heroes of one class...
And now I won't be afraid to say that this is a strange statement! :D
There's an interesting nuance here, I would even call it a phenomenon - if you set only heroes of one class in the editor, and simply don't allow all the others into the game, i.e., uncheck them in the settings, then, nevertheless, a hero who wasn't initially there will still appear in the tavern, a hero that you "canceled" along with everyone else. Only after purchasing this hero will the others - colleagues of the same class - start to appear. That's how it works. I don't know why this happens, but it's a fact...
Amber, what do you say?