We have 2 average sized burms and a retic that's still growing. We would never think of bringing of them out together, not just because they may fight. It's for safety concerns as well. One of these large snakes can turn in an instant from being well behaved to being an absolute psycho. Trying to get one into a viv is a bit of a handful, never mind adding another on to it. The calmest snake we've ever owned is our female retic. She's never shown any aggression what so ever, so calm and a joy to handle. But we wouldn't trust her as far as we could throw a bus, we are definitely not afraid of our snakes, but we treat them with a lot of respect. Dannys idea of seeing if you can get to handle a few adults is a good idea but it won't prepare for keeping one of these large snakes in your own home