I don't get all this "turned seat/same level" thing at all.
Our traveling friends have a good old fashioned 24 foot Jamboree Class C motorhome with a cabover bed built onto a Ford E350 cutaway van chassis - in other words, a classic Class C motorhome. Their cab passenger seat even rotates to face back into the coach area.
Their motorhome's Class C flooring is all on the same level ... the same level including the cab's metal Ford flooring all the way to the back of the coach. The "levelness of the cab-to-coach flooring" has nothing to do with the "Class A" or "Class C" motorhome designation.