There's more to it than that, wherever Mourinho's been he's always had an aggressive ball winning CDM, Matic, Essien, Makelele to name a few. Matuidi along with Kante foot the bill and are the type of player he's still missing to play his system, Pogba is a luxury player and if Mourinho plays his usual 4-2-3-1 with Zlatan up top and you'd presume he's looking at Rooney being centre of the 3 pushing up to support and play alongside Zlatan, where does that leave Pogba if he signs?
The signings and system Mourinho plays it's a Matuidi/Kante type player he's missing, not Pogba