Yep, and combined with those times when it never gets past the flop (only 3 cards, not 5) or here is no flop at all (action ends pre-flop, so zero cards), it's gonna be a LOT less than once per orbit.
I think a better solution is to force the Zombie bleed on the next hand whenever EITHER red king appears as a board card (and a double whammy forced post when both appear). This will actually be much closer to once per orbit in actual play -- and anything less is probably not enough pressure on the Zombie to make any difference in game play (and certainly not enough to overcome or significantly diminish his double-stack advantage).
It would seem to me the perfect opportunity for a custom Bleeding Zombie button to be created and utilized. He could even be holding the two red Kings in his hand. Sure, nobody's gonna forget, but hey, this is a chip forum -- so new chips are required, amirite?