The compressor comes on and off in normal operation, once the evaporator is cold enough only the fan runs until it warms and the compressor starts again. You would be running one compressor until it shuts off and then turning it to fan to keep it from cycling until the other unit is cold. It would be a pain but doable.
A second option would be a box fan moving the air away from the 15K unit. It's compressor would run more and may at least keep you comfortable.
In the end I think a larger generator or set of generators is called for. A pair of 2000s can't be quiet pushing a 15k unit so maybe a larger Champion wouldn't be that big of a difference. The big Honda inverter would be nice if you could swing it.