The reason I ask this is because when I was parked at FSDT's KORD scenery Gate H8 with an American Airlines plane, the conveyor belt truck and air stairs have United logos on them even though I have an American Airlines plane loaded.
This was discussed many times on the forum, and of course is also explained in the manual. The choice of ground operators is NOT tied to your own airplane. It would be wrong if it did, because it would lead to unrealistic situations were you *always* find your own ground crew, in any place you fly, which is not the case, especially if you fly internationally.
Instead, the choice of operators is linked ONLY to the atc_airline_codes of the PARKING spot, which is the correct way of doing it, since ground operators are local to the airport so they are tied to the parking spots, and you are normally supposed to park to your own airline terminal or at least to a terminal your airline has a partnership with.
As explained in the manual, and more extensively in the documentation that comes with the PaintKit (which might be worth downloading even if you don't intend to paint, if only to read that documentation), there's a scoring system that assign a score depending on which airline codes the selected parking has, but in case of ties, the selection will be random between all candidates with the same highest score.
