And Di Canio was garbage, even though he had kept Sunderland up. Sunderland rightly pulled the trigger early rather than let the situation fester. Same with Mike Phelan at Hull - perhaps if they had appointed Silva earlier, they might have stayed up. There are as many cases of misguided patience as excessive short-termism.
Rather than cherrypick analogies or precedents which settle nothing, perhaps it's easier to treat each case on its merits and trust what you see with your own eyes. Do you see progress under Pellegrino, however incremental?