Yeah I agree Sarri would be good. My top pick is Conte, but I get that he could well be lured away by a Champions league contender after a year. Sarri is possibly in the same category, but it's still worth the risk.
I think the biggest problem with appointing a manager like Santo is that some of the better players will use it as an excuse to leave, DCL to man Utd, Richarlison and Digne to Madrid. That might happen anyway but it gives the players an excuse, citing a "lack of ambition" from the club.