Not to be badgering you, but you still didn't answer -- male/male pair, or male/female? I'm sure two males could fight and one male could terrorize one female, so not sure which is the lesser of two evils.
And if trio, what sexes? PS I had 6 pandas but lost 2 - haven't decided whether or not to bump them back up to 6 yet but now that I'm staying away from loaches I may.