I don't think Arsenal have done as well as people are suggesting. Pepe could be good but they've lost the creative influence of Ramsey and didn't replace it. Iwobi another who created a lot for them and they're left with Ozil who has been hit or miss at best for a while and the loanee from Real Madrid. Tierney coming from Scotland to a proper league will be a big step up who might need time to adjust and David Luiz has never been a solid defender and he's getting on in age.
Man United I think have got quite a lot weaker. Massively overpaid for Bissaka and Maguire. Lost Lukaku and signed a teenage winger. Where will their goals come from now?
City I think have done the best business. Two top players which are big upgrades for their positions.