Well, SFB isn't this SFB uses bloom filters to discriminate flows while this uses sampled queue occupancy.
It would be interesting to see the two compared in simulation. I'd expect SFB to be more fair until its hash tables start saturating and then CHOKe to be more fair after that point.
It might be interesting to combine them, but I'm not sure what a proper update rule would look like because the CHOKe matches are stochastic. I suppose you'd have an update rule for the blue constants that clocks two different values through a filter depending on the CHOKe match status. In effect, you'd have SFBish behavior until the buckets saturate and then each saturated bucket would behave CHOKe-ish.
Unfortunately, as described, CHOKe is not hardware friendly at all. The random queue access can be pipelined (or, better, replaced with a single memory slot remembering a random flow at the time it was enqueued) but I don't see an obvious way to drop both in the case of a match without taking more memory bandwidth than RED or even SFB like schemes.