Zohltok seems to be as advertised. I think if you look over the course of his career, you'll find that his play in Nashville is consistent with his play over the last 8-9 seasons. He is, at best, a 3rd or 4th line center. I will say that his stick work along the boards is above average. He seems to have a knack for getting the puck out of scrums.
In a 4th line role, I think he is better then Arkhipov. Legwand is working out on the 2nd line, so that leaves Denis out of the mix for the time being. Would you rather have Denis shooting pucks into defenders shin pads, or Zohltok working the puck out of tight situations on the boards?