Thanks for the responses. My tank is not heavily planted, but I do have plenty of hiding places - among the plants and some rocky areas. Maybe I will try getting 3 at once. The RT I have seems to enjoy chasing everyone at feeding time, but then doesn't bother the rest of the day. Also, he is not that large yet - maybe 3".
75g planted tank, with Eheim Pro II and ECCO 2235, 2 Hagen CO2 Natural Plant Systems. 210 watts light.