honestly, lots of people would say that unbonded rabbits will fight through the cages... i have never had this problem with ANY of my rabbits...
any time we've ever added a new bunny we immediately introduce them to the clan (through the cages) and have their cage close to the others but not with in paws reach.
the worst is one rabbit will send a paw through the cage and punch another rabbit, who will either respond or run away. there are random "jabs" here and there but its not overly agressive.
i have rabbits who live beside each other but can't stand each other out at the same time... i believe tolerance gets better with time. if the rabbits are used to the new rabbit smell usually there is nothing they get worked up about...
all my males are fixed (2) and my 3 females are unneutered. i bonded the two pairs with both females unfixed to their husbunny.
every bunny is different of course, i guess i have been lucky with my bunnies!