These dates being quoted now, e.g., 2020/2023? for 35? deployment availability on whichever deck is available makes a mockery of the 2016/2018? dates that were being touted this time last year.
The F-35B is the first model being produced, then the F-35A, then the F-35C. Since the USN is buying the FA-18E/F in as many numbers as they can - at rock bottom prices - as a "stopgap" - they are also quite sanguine with any slippage, and even cancellation.