I agree with both posts. Maroons are nasty. Most people don't realize how nasty until they have owned one.
Your best chance would be to get them to host a nem on the opposite sides of the tank. Maybe introduce the pairs at different times, so that they can settle into their area before introducing the other? I'm just not sure which pair first would be better. If you decide to go this route, please make sure to keep a close eye on them, and be prepared to separate them if need be.