The 2018 squad in paper was miles better than the 2013 one.
If you dissect the 2013 squad: Scholes retired, Giggs retired within a year, and within two years Vidic and Rio retired , Nani went to Portugal, Rafael was struggling in France, Fabio couldn’t make it in Championship, Buttner no idea what he did, Anderson went to loan that season in Fiorentina and couldn’t start, Cleverley was shipped within a year in Everton and failed there, Welbeck failed at Arsenal, Kagawa went back to Klopp who was fighting relegation but couldn’t start, Jones became perma-crock, Evans was shipped to Hull City. In pretty much every department - in paper - the 2018 squad was better.
On achievement, the 2013 squad was better . But then, on achievements, the squad Mourinho left was better than this one, until gets proven otherwise and this squad does something.