possible, but no guarantees. as long as they set up their territories at opposite ends of that 6 footer, they may be fine...if they all decide to establish base camp in the same area there could be some fighting.
Maroons can be a major pain, though, especially when they are mature...how big is the maroon compared to the femake Perc? Which are in the tank now? (adding the maroon will probably be more successful than adding the percs into a maroon's home)