Yes, there's no problem with this. I've hatched heavy breed chickens (for example, Light Sussexes and Wyandottes) in the same incubator with little Sablepoot bantams. Having been hatched and raised together, they're the best of friends. The only difficulty may be if the bantam chicks hatch earlier. You'll need to take them out of the incubator once they have dried off, whilst leaving the other eggs a couple of days longer. That's no problem as long as you are quick in removing them. Generally speaking, to avoid that issue I prefer to use separate incubators to hatch bantams and large breeds. But then, I'm lucky enough to have more than one incubator.