I had 5 blue loaches and 12 clown loaches
I found the blue loaches were almost always hiding
Also found they grow much quicker than the clowns and once they get big, when they do come out they often chased the other fish around and picked on them
Not to the point of nasty aggression but enough for me to see that some of the fish were not happy and the clowns were hidding a lot
I eventually re homed the blue loaches and kept my clowns