Our biggest issue is that we don't have the players to change the system. No wingers, no pace, no creative spark.
Personally I'd play a back 4 of Ng, McGuinness, Morrison and Bagan. Bacuna, Pack and Ralls in the middle. Collwill, Giles and Moore as a front 3.
If we must persist with a back 5 then the two side centre backs have to have some pace. Ng has played there in previous clubs as have Pack and Vaulks. Back 5 of Sang Ng Morrison Mcguinness Bagan maybe.