Coming such a long way the people of Northern Ilsabard have surely is a great feat and shows a lot of dedication to the cause and endurement.
But let's not forget another aspect of how they got that far. Don't read if you haven't finished 4.4/4.5 MSQ yet.
They were able to overcome it because the knowledge for their technical advances and the expansion to an Empire was possible because they had their strings pulled by Ascians, who already had the knowledge and surely all the resources needed, since Solus had been the one to iniate all their advancement.
My take on it is that the people of Garlemald only came that far because the Ascians wanted them to.