Say what you like about Mourinho. Whilst he was here there were matches where he would directly influence the result in the 2nd half with his changes. The most vivid example i can remember off the top of my head was West Ham away 2017.
https://www.bbc.co.uk/sport/football/38433519.
We were typically sluggish, but Mourinho was quick to make changes at half-time to the shape, taking advantage of a red card. He moved Carrick to CB, Mata came on, then on came Rashford. Our goal was made shortly after by Carrick swinging it out from CB to Rashford on the wing, then he cut it back for Mata to finish. Goal made by Mourinho's changes.
I have yet to see Ole make such an impact on us in a game, and that's the sad reality.