Echelon question

So I've been playing this game while now, got a lot of the 5 stars, not all, and I have my main echelon maxed out team and everything which is a simple ar/SMG team, question is, I know that hg/rf and mg/sg teams are also good to have, what is a good composition of each one that I can work towards that mesh well? Assume I have all for context.