Mostly all songs on SC were only put together/arranged by RZA, not literally produced by him. Nutmeg & Ghost Deini's samples were still founded by Black Moes-Art & The Blaquesmiths. Theres a difference.
But your absolutely right about Rumble being a Deck beat.
Wu-International: Are there any songs you have produced for Wu-Tang and its members that remain unreleased to date you might want to share with us?
Inspectah Deck: I don’t know if there is any unreleased music, there is certainly a lot of tracks I’ve produced, like “Kiss of a black widow” on RZA’s “Bobby Digital” album. I’ve done “Elements” and “Spazzola” on Meth’s joint, Ghost’s “Stay true” which is the flip side to “Elevation” on my album “Uncontrolled substance”, you know ... just plenty. I did “Rumble” on U-god’s ... I mean, every Clan member I have produced for. GZA’s “Beneath the surface” Streetlife’s “A star is born” ... it’s so much, but I doubt if there is something that’s unreleased that you haven’t heard yet. You probably heard some things but just didn’t know it was me that produced it, like “Visionz” off the double album, it’s so much man, but I appreciate those fans that have taken the time to notice all that for me.