Just reached Diamond and I only know 4 characters well, how screwed am I ?

I knew this was coming but I was too lazy to care.

I only know cloak and dagger, Psylocke, Peni Parker and Moon Knight (in that order of best to worst).

With bans beginning to be a thing now, will I get away with these 4 for now while I learn some other characters? Or do I desperately need to expand my arsenal right now ?