Yep, when they start to mature they need to be seperated to keep them from fighting...even some of the females will need seperated as some are just too aggressive to be kept with others. (some fail at getting along with others, Lol).
Just get a few jars ready and some black construction paper and a shelf. That way you can separate them easily and reduce the stress if they see each other through the jars.
i have found the larger females to be among the most domineering in my plakat grow out tank. feeding time is usually when things get a little crazy, more like feeding frenzy it would be great if all the fry grew up at exactly the same rate but unfortunately you do get size variances and the bigger fish (not always the males at first) are the pushiest. we just went out today to buy another shelf as we will be jarring more of the juvenile plakat this weekend. they are all on pellets at this point and have voracious appetites.