Class A is a broad term in that it covers from short gassers to really big diesel pushers. Many small gasser A’s only have a 4K watt gen, mine included, but it also only has 30 amp service when plugged in. Whether plugged in or on genny I can’t run everything at the same time. Some A’s have a power management system that will overcome this issue by automatically shutting down certain items when power is needed elsewhere.
Years ago I had a Airstream motorhome that had 30 amp service, but a 7500 watt gen. I could run more on the gen than I could while plugged in. As an example on shore power I could run either the front or rear AC, but while on the gen I could run both and more.