I don't know if it is a glitch or what but it seems that when I move a player to a new position the other players around him change their overall. Lets say I have a RM who is a 68. So I put him at the position and put a 64 overall CDM (in the CM spot) next to him and he stays at 68. I then replace the CM with a 67 overall LM or CAM and the RM drops down to a 64.
If this was done intentionally then it is pretty cool. Basically you can't just switch players to positions they do not normally play because it will affect how other players around them are rated. It makes you have to find a team that is cohesive enough to play together. Or maybe it was unintentional and it doesn't mean anything......who knows