I don't think it's that an absurd a suggestion. United have a far greater chance than Arsenal and Liverpool, and a better chance than Spurs (who actually look weaker this season). United have the best defence in the league. Their problem last year was scoring goals, and they've gone and signed the most consistent Premier League goalscorer over the past few seasons, after Kane. Zlatan's in talks to return when he's fit, too.
Chelsea weren't even challenged last year but they didn't have the extra pressure of Europe, which they will do this time around. Their signings haven't set the world alight and I think they, too, look weaker this year.
Realistically City should win it at a canter, but that was the case last year too, and something always goes wrong at that club. I think their only real challengers will be Chelsea and United.