3N-5-2 Flat is as terrible formation, because most managers play with two strikers. Your defense will suffer a disadvantage if you don't have two or more defensemen than your opponent has strikers. And lining up your midfielders in a flat formation makes it weak to long passes.
With your high number of weak players that are four stars or lower, I would go 4-2-2-2 Hexagon and won't suffer too much in possession.
Good for you that you still manage to find other teams that are even lower rated than yours. At my level, I have not seen a human team (not computer-generated filler nor an abandoned team) like yours in the past two years.