It's different because they are allowing them to serve as Officers in the AFU rather than being trainers. Rather than saying, "This is how to target this system" they will actually be doing it themselves.

Taken to extremes it leads to the possibility of them flying the fighter, crewing the tanks, etc. which at the moment, under current policy, they are explicitly forbidden to do.

The foreign mercenaries were different although they seem to have dried up (or died off).

Anyway , never mind. Good luck to you all.