I agree with David/Slugkiller that the multi-bulbilled one is P. chunii. Not surprisingly as I bought the plant from him
. But, during flowering I did some research and I am convinced that it indeed is P. chunii... BTW, this species is one of my favourites! The bulbils on top are somewhat larger than those of P. humilis and I find them easy to propagate.
The succes of propagating top-bulbils of P. humilis depends on the clone you have. At least, that is my experience. I was succesful this year with 25 bulbils of a clone obtained through Eric Locke a few years ago. Other clones were difficult. Or they did produce two top-bulbils only (P. humilis Bigu Gompa from Koos Wubben).
I use a potting mix as despribed by Paul Cumbleton, but for the small bulbils, I cover it with a mix of very finely cut sphagnum mixed with perlite. The bulbils are not lost in the spaces from the coarse mix en are less subject to desiccation due to the fine mix surrounding them.
Hope this helps..