What do you mean by "poseurs"? That Ro could've spotted Eddington and Riker as Maquis before anyone else? How would she be able to do better than anyone else at spotting Maquis?
W. Thomas Riker deflected O'Brien by offering a cold shoulder, and he would've had to have done the same with Ro. As for Eddington, was there really any indication that he was Maquis before he defected? What would she be able to see that Sisko didn't?