Two of my labiatus lip locked for about a week and then the larger one won out, since then I've seen very little aggression from my labiatus.
My alpha norte will sometimes go on a rampage and chase everyone but this only lasts about 30 seconds. When I had my gymnos in with my leopard ctenopoma, the alpha male and ctenopoma used to chase each other but never hurt each other. He is also kind of the peace keeper in a way, he will break up any other two fish venting or sizing each other up.
I wouldnt worry too much about your little guys, imo are just trying to establish who is dominate.