Although said mercs will simply be highly-motivated amateurs flying stuff out from the boneyard to get playfully 'shot down' in simulated combat.

Still, it also presents the opportunity to train the mercs as much as the regular air-force pilots.
-Would also be pretty good for business if a company became well-known as being one of the better 'aggressor' squadrons in top-gun, if they can manage such a feat.