I agree about Matuidi, Ricky. He's a Mikel type of player. I think you're underrating Perisic though who's a skilled, ambidextrous winger with genuine playmaking ability. He's better than Mkhitaryan in my opinion. That's not a guarantee that Mourinho will use him or use him well of course, but I think he's the type of player who will make a tangible difference on the field and not just contribute with a nice name in the match program.
I could be wrong and he'll flop completely of course. I hope it happens. I don't see it though. We saw how good a scrub like Marcos Alonso could be this season when he's given a clear role and proper coaching. Perisic is a better wide man, and when you look at how much importance Mourinho normally put on wingers you have to think Perisic will add quality to United.