Ordering a new in-development model and existing models?

[Flightsimer]

If you order a new model of a family that is in development that wont be delivered for say 5 years, will the system award slots for models already in production ahead of those slots for the in-development models?

ex ordering 737max as a launch customer and then ordering 737NG's afterwards as a top off/stopgap order. will the system award 737NG slots prior to the MAX slots way out in advance or will those 737NG slots be after the 737MAX slots?

[groundbum2]

I've found the NGs will be slotted in befpre the MAXs, and if there are too many the remainder will go after the MAX deliveries. I've seen AWS be less efficient when the orders collapse down a bit (ie it starts off with 2 deliveries a month then often moves everything up to 3 a month). I've seen AWS not always move the NG delivieres initially slotted after the MAXes shuffle in front as space is created.

Simon