Koulibaly vs. Lindelof is a skewed stats comparison to begin with considering they're not only playing in entirely different teams where Napoli has had a considerably better season than United, but also that these teams play in entirely different leagues.
Now I'm not against the contention that Koulibaly might be a better defender than Lindelof, but this kind of comparison makes a poor argument since it doesn't consider the facts I just mentioned. Better to at least compare him with other defenders in the Premier League, rather than a standout defender in some other league.
This being said, I'm not sure what the point of this argument is. Of course there'll be plenty of other defenders in other teams with better stats than ours - we've conceded 54 goals! Why is what's interesting, and you won't find the answer to that by looking at stats like these.