I think it really depends on the beardies and their personality. The first two we had were best friends. They slept together and enjoyed the same basking spot, the bedroom window with an 18" reptiglo 8
uvb bulb about 6 or 7 inches above them balanced upon two bricks. The two we have now we would never house together, they are about 6 months apart in age, I think anyway as I have no idea how old Speedy is except that she was about 6 inches long and was clearly sexable when we got her almost one year ago this month. To have them out in the room or the window together doesn't cause any fights between them. We never leave them that way when we are gone from the house. Speedy tries to sit on Zoom Zoom once in a while, but that's the only domination I see from them. Zoom tries to sit on Speedy sometimes, but not as often. She'll try that mostly in the
bath. But neither of them has tried to "attack" the other one. Once this last week Zoom headbutted Speedy but not to the point of injuring Speedy and she hasn't tried that again. This is why I think it depends on the beardies whether you can have them out or not. I've read about some beardies attack their reflection in the mirrors. Ours just look at theirselves. We are holding them in our hands and I don't know if that makes a difference with them or not, but out of the 6 beardies we've had we have never had one the attacks themsleves when they look in the mirror.