Are you planning on breeding? and really spent the time doing the research and preparation for all the offspring? If you are unsure or say no to either of those questions, don't even think about it.
Regardless, I dont house any of my reptiles together. IMO it is way too risky (fighting or killing each other as well as disease/parasite transmission, also in nature leos are not a social animal, so why force that upon them) and since you need to have a separate set up ready for IF anything happens at any time and for proper quarantine, I would just use that separate tank.