[Nate]

Well Glukkons advanced into alchemical sciences, abandoning their spiritual ways. It would probably be hundreds of years before they were capable of building complex machines, but they had the time as Mudokons remained harmless naturalists.
They hid away and conspired against them for ages, recruiting other creatures (Sligs, Vykkers) to their cause, bribing them with precious metals and false promises. This collaboration of species hastened their industrial progress, and eventually they were collected and advanced enough to wage a war on the Mudokons.
The Mudokons lost, arrows versus bullets kind of deal.
Many were slaughted, the queen at the time was kidnapped and subjugated to birth a workforce, those that remained hid away in the deepest temples, and I assume this was how it was for decades to come. Then Abe set the wheels of revolt in motion.

As to their physical characteristics, I don't think Glukkons we're always so frail and stupid, especially if the design of the Oldgers is anything to go by.

Yes, but my question was how did they manage to obtain such alchemical and industrial prowess without usable arms?

Also, Sam wasn't kidnapped. She chose to join the Glukkons.