DC or DCM ?

I have a dual position DC/DCM playing centre half , his best position is DCM but as he is dual position he is the best of my centre halves , the DCM I have , has better centre half stats than my dual position centre half but is only a DCM , does it make a difference if I swap the two over ? How much difference will it make as both players are stats wise better in each others position ?

The player with higher creativity and passing should play DMC.