Tonka is a complicated beast, and a bit of a pig to keep serviceable
Added to which, it's a long way to send for spares/tech support. Makes more sense to overman/over skill the 1435 team, than to LEAN it so much that you have, potentially, no aircraft serviceable just because you've saved a few bob.
You'll probably find you could run twice the airframes on far less than 2 x 56.