as i said, use right back, centre back, left back. 2 CENTRAL defenside midfielders, not wide - left centre and right centre. use up arrow for ur central midfielder. i beat teams with 5-6 qualities higher than me with higher possession and more shots.
yes. always try to have 2 players for every key position and also when u sign players, show preference for players who are versatile with atleast 2 positions. u can't always do that but just look to strike a balance between quality(preferred players) and utility(substitutes who can play multiple positions). Utility players can be game changers in key games against stronger teams when ur trying to stop the opponent and hit on the break.
P.S. make sure u watch the match and make sure the player ur using in CDM has good defensive and physical attributes. if he makes mistakes, make sure u have a backup player on the bench for that position. i always change players who make mistakes against stronger teams or in big games, it means they're nervous. watching the game and reacting quickly are key to beating big teams
i always watch my games, and i have kept subs for every position, i literally have 2 teams, but for specific formations, i got one DMC only coz i rarely use a formation in which i'd use a DMC, i've just kept him if i need him. so i guess the normal 3-2-3-2 could also work?
st st
MC MC MC
DML DMR
DC DC DC