When I was shopping, the Winnebago Sightseer had the same interior equipment, trim materials, and color options as the Minnie. The (same price as Minnie) Itasca Spirit had different materials and colors from the Minnie, but same as Itasca Sunova.
I expect if I looked closely at one level up, MinnieWinnie vs Voyage, I would have seen the similarities there, but I wasn't shopping at that level.
Interior layout similarities are even more common, for manufacturers that make both C's and matching size A's. The overlap used to be limited, 29-32 feet, but there will be more size overlap now as the smaller size A's come back on the market.