Mark, nice topic, even if it calls for rampant speculation.
My first thought was that maybe he was trying to one up Mac's U shaped greens at UM and Crystal Downs, but RCC was built earlier, so maybe Mac liked the idea but thought it was impractical, and didn't carry the "U" completely around to form an "O".
I agree with those who say it was probably just meant to be a "conversation piece" type green, and also not surprised that the pins find their way on most days to the most accessible front spots, which may (from memory) be easier to putt to from above the hole.
Or, as Mark speculates, it was just a different way to subdivide a big par three green into smaller compartments, which isn't a bad idea. This was before the era of PGA Tour pros acting as consultants, and their typical question of, "What if I hit it HERE?" which tends to water down most unusual design ideas, LOL. Or for that matter, before supers were willing to speak up about maintenance problems, like divots on greens.