So, Tracy set up an x-pen configuration that helped my buns be together 24/7 and yet kept them from killing each other. It looks like this:

The entire pen was about 3’x6′. The idea behind it is that the “L” shaped fence area broke the pen into 2 sections so each bun had their own and could get away from one another. In addition, if a fight started, one of the buns could hop to the other area to get away and with the barrier in the middle, it broke up the natural urge to charge since something was in their way. She put them in there and never worried again.
She continued with regular bonding sessions, pushing down the head of the aggressor to have them submissive to her. The trouble is that we all know that WE are submissive to the buns – they’re the Alphas. In a strange place with a strange person, that isn’t the case.
If you plan on doing this, I’d suggest monitoring them for the first couple of hours to make sure that one isn’t dead set on killing the other. Maryann only had a strong dislike of Dono, not hatred. 