The basic resources for Sulphides would be the same - and actually far simpler. They just needs to batch mold some kaolin clay figures in wood molds and then fire them and then leave them in the hot kiln.
Then a very small gather on a punty for half of the marble, cut the piece and drop into a half sphere cherrywood mold, the heatedt figure is dropped and then pressed in, and then another snip of glass from the punty - and then it is puntied and rounded in the same cherrywood mold.
No need for colored glass, cane pick-ups, cane pulling, frit rolls (onionskins). Its actually a very easy process.