Oddly, it's almost a What These People Need Is A Honky situation -- blessed and God-dispatched protagonist brothers for whom everything goes right, weird foreign servant whose respect they earn and who constantly sacrifices his comfort for their benefit, coming from a blessed land falling into disrepair and bringing the gifts of Golden Galkis (their home city) through all the lands they touch. They also do things like bring bows and arrows to the tribesmen they meet, because the tribesmen hunt entirely with thick spears from cowback, and apparently nobody ever, y'know, brought bows over during the regular commerce between advanced countries on both sides of them. Or horses, but there aren't as many horses in the books so far.
Only one major difference springs to mind -- they're brown-skinned and brown-haired, mostly with vaguely Asian-sounding names (what nationality would "Kerish Lo-Taan" be?), and most of the people they're dealing with are white folks. The servant is pale white, if toad-shaped, and most of the primitive natives are either green-haired and -skinned or golden-skinned and white-haired like the bowless cow-riders above.
So then, do I call it What These People Need Is A Chink?