I think those mixes are okay, however, it is difficult to breed multiple species in the same tank. You have a high chance of them cross breeding. I would encourage you to do a little larger groups, and then when you are ready to breed them, you should move them to a species only tank. Its great to grow out your groups together, they learn to tolerate each other better and they are not as aggressive towards each other, in larger groups. (6-12). It is the female that picks which male she wants to spawn with, and they do not always pick the right male. And multiple males in your groups are good, this will take a lot of aggression off your females.
Regarding Metriaclima are going to get bigger, and they get pushy, and like to hog food, nothing like the sweet Saulosi!!