In terms of overall squad quality and depth (assuming full health), City and Liverpool are the clear #1 and #2. You can make a good case for either United or Chelsea as #3, but I think Chelsea is a deeper squad, so they get my #3 and United #4. Spurs and Leicester would follow.
So using this metric, and given Liverpool's horrible injury problems, United is probably achieving at par or slightly above. Chelsea massively underachieved under Lampard, but Tuchel is getting a lot more out of a deep and talented squad. Leicester is overachieving, though they too have to deal with some key injuries at the moment. West Ham and Villa are definitely overachieving, though I always thought their talent was underrated and last season it felt inexplicable that they were both in relegation trouble. You could say that Wolves have really underachieved, but selling Jota and losing Jimenez to such a serious injury really knocked them down a few levels.
Feels weird not to mention Arsenal. They remind me of United from a few years back — some nice pieces, but lots of deadwood and young prospects who aren't ready yet. If they're patient and stick to their plan, I think they'll be okay.