I can’t say I agree in general, he was very consistent during his first 2 title years, and in his first 2 title defences for that matter and in 2009, Rossi was just better that year. Most of his off days in his latter years at Yamaha were related to damp conditions, in which he previously hadn’t been a complete mug prior to the two clavicular fractures in 2013.
We will have to see how he goes in conditions not suited to his favoured tire on the Ducati. My guess is that he might go down to 4th or 5th but not any lower now the bike has actually worked for him.