So true about wishful thinking! Tribal loyalty was not the best wording I could have used. It's not that I think they are bound to protect their original tribe, but rather that what trust they do have established is with their old tribe. Except possibly Colton.
While Monica and Christina are going to be open to whatever options they find, Greg will not want to change his alliance with four members of the misfits together. Leif, we just don't know yet how he feels. Jonas, has worked to integrate himself with the guys. He seems to me least likely to jump ship.
You did point out these photos back in Ep 3:
I am hoping they do bond, we did not see that scene broadcast, and I wonder if it was even pre-swap.
In order to pull off a blindside "chop the head off the leader" type move, they have to trust that everyone involved will really vote that way. That is the kind of trust that is hard to come by shortly after a swap. However, these guys have been living side by side, and we don't really know what bonds may have formed that the edit has held back from us.