well...if they are anything like their cichlid counterparts, the big one will most likely establish his "territory" and show aggression towards the younger ones when they are introduced...which is what happened with my large angel when i finally gave her some tankmates...but then again, she has acclimated nicely to having others around so perhaps he larger one would get used to them eventually...you might also try a tank divider when you first begin to introduce the smaller ones...for a week or so so that the large one can get used to the presence of the small ones....good luck!
Bri
Bri