What year is the Sequoia? I ask because they went through a couple of design changes on the gray and black water connections.
On the '06 model that I have, the gray and black water both terminate at a standard 4" bayonet sewer outlet, not a garden hose variety. That's because mine has an actual 6 gallon black water holding tank. Other years, they have a cassette potty so no need for a black water drain underneath.
It irked me that Fleetwood put both the black and gray drains into one 4" outlet. On most TTs that have both types of tanks onboard, you dump the black then use the gray to "rinse" the lines. Not so when you only can hold black water in a tank.
Without a gray water holding tank, I have to hook up my blue tote to outlet and leave they gray valve opened all of the time. Unfortunately, there is some residual black water in the outlet and that gets into the blue tote. Since at least in my mind, it makes sense to treat gray water and black water with different handling processes, I hated having to treat the gray water blue tote as black now because a small leakage or residue.
So, the '06 is definitely a different critter. Other years around it may be the same but I think they changed up the design to go back to a cassette potty on the highwalls.
To me, it didn't really matter having a "real porcelain toilet" as Fleetwood made it a selling point, but I sure hated the shared outlet to the point I actually divided them into separate outlets. Pictured below is original outlet on the left, with the gray line capped off and on the right is the new gray-only outlet. It makes life a little easier except for the rare occasions where I have full hookups. Which is like never anyway, but that's easily remedied for the odd times when it does happen.