That’s interesting…
I have 5 rabbits, and I got them all to bond with each other, but it was easy for me because they were all little when I got them/rescued them.
At first, I got a male and female, they both got along the second I put them together. After this, I rescued another doe, and two bucks. They got along very well, but as weeks go by, the two younger male would always fight.
I separated the two, but I placed them near each other in separate caged (Not close enough so they can make contact).
After a while, they seem to get less hostile with each other (they stopped trying to bite at the cage to get to the other).
The progress improved when I would take one out on my bed and held him, while I let the other one wander around the bed to smell everything. Their prescence seems to not bother each other anymore. They ignored each other at first, but now they sleep together, eat together, and binky everywhere with each other. (the two are unneutered males-4 months old)
So, I suggest you let them be in the same area together but don’t let them make contact yet…Rabbits eventually adapt/get use to their surroundings, and won’t find another bunny/person a threat anymore when they’re so used to the other one. Almost like humans, really 