I'd much rather just do the following this summer.
Keep Smalling, buy Sancho even if it leaves the team with £10M left in the transfer kitty.
If a few players can be offloaded, get Grealish for around £40M this summer and 20M the summer that follows (offloading Jones, Rojo, Lingard, Dalot) or Thiago if he isn't liverpool bound.
Next summer buy a player to partner Maguire, offload Smalling.
Renew Pogba for 4+ years.
Chelsea have been really shrewd in the transfer market, even Thiago Silva is good business, United are really the biggest club in the world but are so slow at getting deals done.