The model for demand for simulators in F-35 has already been laid out for the US by F-22. Of course, the lack of two seat trainers for both types will front-load OCU courses where the FMS will need to provide all the pre-solo stuff as well as all the academics phase systems, procedures and emergency training. So it's important to remember that the 50% is not an even spread across the course, nor between OCU and front-line flying.
It's important to understand the requirements there, I think.