According to Mark at Candyland/Tog/whatever_their_name_is_this_week every asian agency in town is a sort of "offshoot" from him. He says all of the guys running these places used to work for him and now each other. So it is natural they would share/use the same girls. ALLD used to try to explain how this worked before Otto sold the agency.
Short answer would be they are sharing girls at minimum.