OK, well, as far as 2019 is concerned, Sale was likely pitching hurt.
In 2021 he registered a 3.16 ERA in a small sample of 42.2 innings.
His career ERA is 3.03.
I don't think anyone would argue Chris Sale is a 4.40 ERA guy when he's healthy.
Factor in age, and a reasonable projection of his ERA this year would be 3.40 or something like that.