Not sure about Chelsea having a weaker squad, much rather have theirs than Utd's
They've played without Kante & Loftus Cheek most the season as well
I think some of that perception is down to the two managers though.
Before the season Chelsea had a strike-force of an aging Giroud, a player who had failed in the Premier League at Swansea (Abraham) and an unproven-in-England Batshuayi. They had also just lost Hazard and replaced him with a player who had lost his place at Dortmund. Lampard, like Klopp, has players playing to a level that nobody really expected.
Man U just look lost and I'm not sure a single one of their players is playing at their highest level.
The final score-line was harsh but Man U did beat Chelsea 4-0 on the opening day. The contrasting fortunes since is stark as both managers have made their marks.