Completely agree about the DM position. Herrera has been class this season, I'd probably say he's been our player of the season, and yeah it would definitely be good to get a DM in so that we could play Herrera alongside him and push Pogba forward. We need a Kante-like player who has the fitness to go up and down the pitch for 90 minutes, the problem is finding someone suitable. I really hope United don't go for Dier, I know we've been linked with him but I think he's the poorest of the three midfielders that Spurs usually play (him, Wanyama and Dembele) and if anything he's a downgrade on Herrera.
If Mourinho continues with his 4-2-3-1 formation next season then I think there's definitely a space in the three behind the striker for James, I'd prefer him there to Lingard, who's had a really disappointing season imo, and Mkhi has an awful lot to prove too. Personally I want Mourinho to give Martial more of a chance, he has more pace and better feet than Mkhi. Also, don't forget that United have the money from Schneiderlin and Depay, so that will probably cover a large chunk of James' fee. Obviously this all depends on who else United are looking to sign. I wouldn't take James over Griezmann for example, and if it was an either/or situation then I'd definitely pass up James, but if he's coming in alongside a couple of other attacking players (somone like Lukaku, Griezmann, Mbappe, etc) then he'd be a good addition to the squad imo. Also, wages are hardly going to be an issue for United. If we do get rid of Rooney and Zlatan then that frees up over £650k per week in wages, and if it's to be believed that Pogba is on £165k a week then I really don't see United paying James more than that. Zlatan was only able to demand so much because he came on a free and Rooney's wages are ridiculous for a player of his now poor quality. In hindsight United were foolish to agree such a deal, but at the time they couldn't stomach losing a star player to City.