As long as he's no longer classed as a '10 minute wonder' then I'm happy . He's NL/L2 level for me, and had a surprisingly very impressive season playing and learning a new position.
As for Cal Roberts, he had/has the ability to a lesser degree obviously of a Robertson or Grealish but would you take him ahead of Rodrigues or Austin in the system and approach LW adopts. I don't think I would. Yes he can beat a man, made things happen and when on form (pre injury) he was almost unplayable at times. A joy to watch. However there was the other side to his game which wasn't so appealing, defensively non existent, moaned too much for me, and I suspect doesn't work hard enough or with enough responsibility off the ball from LW. He's not a Ruben that's for sure.
All hypothetical but I'd pick Nemane over Roberts as a wing back every day of the week and twice on Saturday and Sundays.