You don't think McNeil & Doucoure in particular looked transformed under Dyche?
I think people take issue with whether or not the manager has improved that player or wonder has that player even improved or are they just been utilised better.
For me, Doucoure who is 30/31, probably hasn't improved but no doubt that Dyche has made much better use of him. The Doucoure we are seeing now is very similar to the one we saw at the beginning of Benitez's time. Dyche and Benitez knew what kind of player he was and didn't have him trying to play possession/slow build up footy.
As for McNeil, there's no question Dyche is using him better than Lampard was. There is also no question that he has improved, he's 21/22, and has just posted his best goalscoring season in the premier league despite being in a poor side, and coming off last season where his numbers were poor.
So in short, the "has the manager improved them" shout is semantics for me. What I can see is a manager who is using his players correctly and as a result we are seeing better performances.