No.
You are saying "Stones got better, so Mangala will".
This is complete and utter rubbish and if you actually watched how they play, you would see that. Last season Stones made mistakes while always trying to play Pep's way. Mangala doesn't try to play Pep's way, he plays exactly like he did under Pellegrini. He doesn't do anything with the ball, he doesn't take any responsibility for our build up play. He just sits and waits, passes it to his partner (in this case a 19 year old with no experience) and hopes they do it.
Then he makes mistakes on top of that. That's the crime. He is making all the mistakes Stones and Otamendi made last season, without showing any of the balls Pep talked about Stones having.
He's a very nice bloke, I hope he does well somewhere where his pace and physicality are enough.