Hey Carl, welcome to the forum!

From memory, I think at least one of the Middleweight robots in the making are using hoverboard wheels and motors and as Joe mentions, they would need support on both ends, presumably with a deadaxle but provided the shared weight and load across all the motors is good, I can't think of a technical reason why this wouldn't work. That being said, the gears in such a thing will need to be checked to see if they are plastic (Delrin or something). If they are, I doubt they'll stand up to a lot of force in MW or HW combat if not suitably protected and adjusted.

As far as controlling them, they are usually a brushless motor, I imagine with sensing. There are plenty of brushless ESCs out there that will handle those with a bit of wiring jiggery. I am trying to recall Ellis's (Magnetar, Pulsar) shop name where he has some of these ESCs but it isn't coming to me at the moment.