very large aircraft tur with a little bit more than 9 crews. That's realistic.
767 have a crew of 2+8. so you need 90 crews per plane. A 7-day schedule needs 7 planes, therefore, you're at 650 flying crew.
But it's not all. You need people on the ground to guide the planes, to handle the luggage, to manage the routes, to make the marketing, to sell tickets, to manage irate customers, to manage all those workers, to repair the planes, etc...
Therefore, 1700 people is not so surprising.
I don't need that many more ground handlers or anything, because the workload spreads out further over existing staff. And if you already have 450 aircraft of that type, you don't need full staff again.
With 1000 aircraft in operation, I doubt that for every next 7 planes I need 5 more high-level management!?!?
And considering that on earlier schedules I needed not nearly as many new people.
I would think more of 500-600 new people (and that would already be excessive).
To handle 1 767 turnaround you need 5 people to handle the baggage (including the loading of the aircraft), + 3 persons for check-in and gate (check-in staff moves to gate after check-in closes) you basically need 4 shifts of these people (to cover the day + free time for each of them) -> 32 ground staff. 2 technicians per plane at maximum (rather 10 for all 7 planes).
I would think more like 50-60 flight crews rather than 90, so make that 350-400 flying crew.
To sum up:
400 flight crew
32 ground crew
50 office staff (incl. route strategies, customer services, etc.)
less than 500 total crew.
The above maths is already the "deluxe edition" absolute perfect version. In day to day operation you have less than half the ground staff, and flying staff is little different.