Given the swimming patterns of the two (and the fact that I've seen them coexist) I'd go for it. Maybe cut the numbers down by 2 or so on each to avoid overpopulating the tank as they grow. I know loaches prefer the bottom and barbs if I remember right were more middle swimmers so they shouldnt have too much of a turf war. and I've seen them in tanks together with good success by one's and two's.
I say go for it
I say go for it