Honestly I see him more on the wing than as a center. Not winning faceoffs is just a hughes issue for me. It's a reason why a player like Bergeron is so good. It's why the Oilers can struggle with McDavid on the ice taking faceoffs. Winning possession is where it all starts. He's really more of a Kane type player. Let someone else get the faceoff, and when they win it get him the puck.
I think trying to turn him into something he's really not hurts the team. Much like McDavids poor FO% hurts the oilers.

He (Hughes) has played centre his entire career, nobody is "turning him into something he's not"

I don't think you understand the point. Playing Center down there is one thing. Playing it in the NHL is another. You can't have your top 2 centers coming in with 40 some percent faceoffs. It holds the team back. Much like McDavids low faceoffs hold the team back. They keep throwing him out there expecting different results but it's not happening. Not winning the faceoff is just damaging it kills momentum and leads to zone exits on the offense and being pinned in the defensive side.
Hughes is not a great faceoff guy, and going up against a lot of the better guys is going to show. Which is why I'm saying don't turn him into something he's not. AKA a faceoff guy. Let someone else take the faceoff and put him on the wing. It's the better choice.

Asking Hughes to play #1 center in the NHL after being drafted would be asking a lot. It plays into the face-off wins vs undersized prospect argument. Usually guys making the jump to the NHL do play wing for at least most of their 1st year.