It is necessary to have a generator in a 5th wheel, I know some have them some don't. We are looking to go to a 5th from our class a and we really don't use ours a lot now.
I am glad I bought the Champion 4000....after 3 years have not had to use it for camping....when boon docking batteries have taken care of unit since only short stays...price fit budget to make it worth having....do use it a lot to run electric chain saw when gathering firewood....start it about once a month to bring it up to temp....good luck