Have you tried putting them to bed earlier? Sounds crazy, I know, but it worked for us. Sharing a room is a good bonding experience for siblings -learning to share their "kid space" etc. So, keeping them together, I think anyway, is good for their relationship. If you put them to bed earlier, they can still get in their bedtime misbehavior, which ultimately really isn't hurting anybody - they are bonding & having fun together - and then possibly get to sleep closer to their real bedtime. (Ex. you want them asleep by 9, but they play until 10:30, then go to sleep. Put them to bed at 7 and let them play until they go to sleep, which will hopefully be by 9:30.) While it is hard to compromise with such little guys, you can give them rules. It is ok to look at a book, play quietly in bed with a toy or talk quietly for a short time. No calling for mommy though. Like I said, it worked for us and eventually, the novelty of fun w/o parents at bedtime wore off and they started just going to bed without all the play.
Plus, then if they are going to sleep at a reasonable hour, then you have the can have some down time and get to bed when you need to.