Cornell's World Cruising Routes, while giving a good average for conditions that he has encountered or read about, should not be considred a Bible. The El Nino of the past few years has given way to a La Nino cycle and what was the norm for the last couple of years may not work this year.
There is a very valid reason that the "mob" arrives in Marquesas when they do. Over the years, this has proven to be the best time to arrive. It's called the Milk Run.
Keep aware of all the weather
around you and be prepared to abandon any schedule.
Never having made this passage
I'll refrain from offering advice as to times.
Sail safe and have fun.