On the subject of McClair I find him quite hard to evaluate but I would not have as high in a best of list of homegrown United players. He tends to get quite harshly appraised if you only watched him as a midfielder after Eric was signed. He's the first striker I ever saw score over 20 league goals for United(first since Best) and he was a good striker. McClair was also a player who Fergie praised for his intelligence and he was someone who could do a good tactical job for the team(e.g. man marking Koeman in the Cup winners cup final).
However, he was prone to go on long goal droughts and he did not have the strengths or variety to his game as a forward player. Hughes, Rooney and Andy Cole are all strikers who could go on droughts but all offered the team alot more than just goals. I'm not McClair only offered goals but not the same level of quality and other strengths as those players. I always rated Hughes as United's best striker and I doubt we would have won a league title if McClair had been maintained as one of the front two.
He was also not a particilarly good central midfielder and the obvious player who could have been improved upon from the first title winnning side of Fergie, hence the signing of Keane to be paired with Ince.
A good player but I don't think he was better than Paddy Crerand, Lou Macari or Darren Fletcher. Evidently, he's not in the same class as Dennis Law or Martin Buchan. Someone like David Herd or Arthur Albiston could also rival Brian McClair