Would it be weakening us though? I don't rate Otamendi in the slightest and have maintained Mangala is the better defender of the two since they both came in. I don't disagree with what you say about Mangala but those attributes he possesses are something you need in this league, and we're missing a defender with those qualities. Put him alongside Kompany and i think he'd work just fine, potentially Stones too if Stones pushes on this season to be the player we hope he'll be. Doesn't have to play every game, but having that option against certain opposition would be beneficial.
Peps had a year to scope the league out now, he's already adjusted his game slightly for this league, it's not beyond ridiculous to think he may have changed his mind on him and now thinks we need somebody like that for when the long ball merchants and teams with strong physical striker come up against us next season seeing as we often struggled against them last season.
We were destroyed by Everton, who went direct with Lukaku and caused us nightmares, Costa and Kane gave us problems in a similar mould, even the likes of Boro went direct and we struggled, same with Leicester away. Like i said, i'm aware it's unlikely, just some out of the box thinking to discuss and one that would tie in and solve some rumoured issues.