My sorority always had very small numbers relative to the other sororities on campus. This is because we started as a local, and were still very small when we went AEPhi. We're growing now though
During rush, we only had to supply 1 Rho Chi whereas the other sororities had to supply 4 each. We also got incorporated into our rush rules, that alumnae are allowed to participate actively in rush for any group below a certain size. (This is only fair as the smallest group on campus has to hold rush in the smallest room available, which is cozy to say the least!)
HTH