This is my thinking. I'd like to see him get one last chance this back half of the season with a run of games alongside Laporte. If we still don't think he's the long-term solution, try selling to Arsenal in the summer for £30m-£35m along with selling Otamendi. Head into next season with Laporte, new CB, Fernandinho, Garcia, and THB.
Imagine going into a season with a fresh from long term injury laporte, new cb with no prem experience, 36 yo fernandinho and 2 teenagers (though good and with potential). That would be worse than what we started this season with and the main reason we have fallen behind.
Ota goes for sure in summer and is replaced, if stones goes, he too is replaced and Id still get another to allow fernandinho back forward (and limit his games)