The logical choice for me, would`ve been Allardyce.
As obnoxious as he is and as limited as he is, keeping teams up with a limited amount of games is what he`s good at.
He`d have taken a short, very well paid contract, with a bonus for keeping them up and had nothing to lose if they went down, as " the damage was already done before he got here ".
De Zerbi is a real head scratcher, as he`s not known for being a manager who is touchy feely and getting players who are fragile and suffering from an acute lack of confidence, playing again.