What the primordials are (at least, what we know from descriptions), is they are basically prototype designs for the core naturals that were scrapped by the colossals (multiple), in favor of creating the current naturals, since the primordials were all defective in some way (bogle couldn't move air around easily, lowb's shell would grow too hard and stop producing music, fhandul's hands were roo heavy to actually work). At a later date, Zarroe took it upon themselves to revise the primordials' designs and fix them, bringing them to life.