I have cory's in with my breeding bristle noses and there is never any problem with the cory's disturbing the males chosen nest log or hollow. In another tank with breeding bristle noses I also have kuhli loaches and even these don't seem to bother the eggs or fry even though the kuhli loaches can often be found sharing the same hollow ornament that the male is guarding his eggs/ fry in. I wouldn't trust Pakistani (yoyo) loaches with any fry, along with quite a few other types of more predatory loaches, cat fish or other fish in general, fry are almost always fair game in most fishes eyes. But cory's are one of the safest fish to keep with even young fish.