parashar

Lets say Im using a pre-made tactic made by some other person. Now if I change the player roles to best suit the player in a particular position, what effect would it have? For example, the tactic has a DM- Roaming Playmaker but my DM has 4 stars as a Defensive Midfielder, and only 2 stars as Roaming Playmaker. If I change the role to Defensive Midfielder, will that be better or will the tactic not be as effective? Thanks!