Is that when the coach's engine gets too hot pulling a hill so you start pitching boxes out the windows?
I believe our coaches' generators have a mechanism for "load building" though. Start the generator, then go start all the AC/HPs at once. Our AC/HPs seem to be on a delay-timing device such that they will start themselves in a gapped sequence.
As far as load shedding, vis-a-vis, the generator, I turn off the AC/HPs manually as fast as I can walk between the thermostats. As far as load shedding goes, our generator is a 12.5KW Onan QD and can run everything electrical on/in the coach concurrently. It doesn't need to shed any loading.