Regression is because he rides for Ineos, I don't need to elaborate on that.He hasn't beaten many worlds the last couple of years and seems to have regressed significantly. Combined with his appalling personality, I'm not sure I would even pick him if my name was Davide Cassani.
To me, Trentin is a much better option. His classics results from this year don't fully show how strong he was, and his win in the Tour was highly impressive. Also, him beating Mathieu and Wout in a three-up sprint in the Euros last year should speak volumes.
World champs last year he was super strong.
He'll be there in the finale don't worry.