Winnebago VISTA 30 or 50-amp?

[Binsky]

I am buying a 30-foot Vista that normally has 30-amp service. However, this coach has 2 roof a/c's and 50-amp service. Is that unusual when the brochure says that 50-amp is not available on the specific model? Is the internal wiring on all Vista's the same, just with different line-in service? It has a 4000 Onan, so that is confusing, as well. Will a 4000 run two a/c's? Thanks for your thoughts.