Go for 3 - the 2 ac's in our 38gk would take a full day to cool off after a long drive in TexUS and/or the couple of times we went to Maumel, Ar....
Was the time I wished I had a genny before having to set up in 100 degree heat - we usually parked, unhooked, plugged in and LEFT for dinner while it tried to cool down.
You would hope the electrical system is designed such that the installed 'stuff' works well together
Not sure about the old redwood, but the only time that I know our coach 'sheds' electrical loads is when we are on the generator and the demand is over the 10k watts the onan can put out.