American already operates about ~400 Airbus 320s vs ~350 B737. [1] United also has ~200 A320s vs ~340 B737 [2]. They both have mixed fleets. Of course the sto

American already operates about ~400 Airbus 320s vs ~350 B737. [1] United also has ~200 A320s vs ~340 B737 [2]. They both have mixed fleets. Of course the story for carriers with a homogeneous fleet is very different. Part of it is surely PR posturing though. Both to look good with customers and to improve the negotiating position with Boeing. [1] https://en.wikipedia.org/wiki/American_Airlines_fleet https://en.wikipedia.org/wiki/American_Airlines_fleet [2] https://en.wikipedia.org/wiki/United_Airlines_fleet https://en.wikipedia.org/wiki/United_Airlines_fleet