Yep. I'll have to agree with that DEF decrease.
Fejsa's tackling is quite accurate, but (above all) it's his ability to read the game and intelligently cover the spaces that really make him so efficient. If TW will do it for him, so be it. Not sure about what exactly should be the DEF value, though.
About *Enforcer, as I said in a previous post he's not the typical enforcer.
IMO, he creates a balance between his positional play and his enforcing, meaning that he won't enforce unless the ball is being played in his defensive range. I could be wrong, but my thought is that the *Enforcer card is reserved for a specific type of player, one that will insanely chase after the ball often breaking his positional play. Fejsa is quite combative, but not exactly in that basis.
That being said, I'd increase his RESP and give him *Covering (as suggested by VUKDS), rather than assigning *Enforcer to him.