No problem with overpowered heroes for me. I mean, my ideal TBS would really be an RPG with additional armies, used for defense and support. Have a party of heroes to advance and other units to hold what they conquer, so they won't worry too much about the enemy slipping behind them, or at least buy time to have them rush back if a strong opponent slips by, and offer support or wear down otherwise overwhelming forces they may happen to face. None of which may be done without those independent armies. And AoW:SM's teleportation gates beat caravans if you want to just move armies between major cities. High-end, costly constructions, not something you just have, but instant travel if that's what you want, while independent movement is available otherwise.

You can still have that. Just make more heroes. You can have 8 out and however many you want garrisoned inside cities. You can make one super powerful hero or split the experience, artifacts and armies between multiple. You can garrison mines if you so desire, leave units at border gates etc.

Having to move 28 independent armies a turn + heroes gets tedious pretty quick.

I'd argue that independent armies, when everything can fight on its own, actually goes against the "heroes" in the title. It's no longer about heroes and their armies fighting, but about "units fighting with occasional hero cameos". Not to mention that it greatly complicates the simple but extremely fun formula of Heroes. Might as well be a different game at that point.

I did list a way I'd be glad to have innovation -- even "roguelite" style. But not what they actually seem to have done with this title.