OK so it's not as I thought at all. I didn't realise that the AMC that likes the wings was an AMC/AML, so he also doesn't mind AMR....
MY theory is as follows:-
GK = only GK(obviously)
DL = DL-DC-DML
DR = DR-DC-DMR
DC = DL-DC-DR
DML = DML-DL-ML
DMR = DMR-DR-MR
DMC = DMC-DC-MC
ML = ML-MR-AML
MR = MR-ML-AMR
MC = MC-DMC-AMC
AML = AML-AMR-ML
AMR = AMR-AML-MR
AMC = AMC=MC-ST
ST = ST-AML-AMR
So each role on the field is able to adapt to two others without being detrimental, of course players with more roles assigned to them will cover combinations of these. As long as a player is playing one of the roles he is comfortable in you wont be penalised.