A lot of people have mentioned that. That's what the rotator is for. You can't truly merge but you can automatically switch back and forth which is roughly the same thing. And clearly that needs to be explained better . Probably the ideal thing would be to have one of the levels featuring one and then you would just see that it could potentially be useful. In any case thanks for pointing that out as the common complaints about it helps me think more carefully about it's importance in the next version .