Not as bad as Mangala or Demichelis but thanks for asking.
You know when you are a part of a shabby defence especially a partner in CB you're most likely going to look **** anyway? When it is your first season especially and he is trying to integrate into new country/team.
Doesn't make him a bad signing, if they sort out another consistent decent CB partner for him he'll no doubt start to show the form he is capable of.
I don't even see how anyone would anticipate Otamendi as a bad signing considering how good he was last season for Valencia, we're not talking an average season, we're talking an outstanding season. Plus I put quite a few names out there for CB because we did need one. Hence why most United fans are still clamouring for one this summer.
Plus Smalling has had shaky seasons and look at him this one, Otamendi could come back to life once their defense gets sorted out.
Otamendi has been below average, and not because he's being exposed. He's been making bad positional errors routinely, though not to the point that he should retire (like Demichelis) or should be sold (City are willing to sell Mangala for a big loss now). Otamendi would have played where Smalling is, and on that point we definitely didnt need that for 45m