Much of the answer to this can be found in the opening scene of Inter Arma Enim Silent Leges
, where during a meeting there is a debate between Worf and Romulan Senator Cretak about the priority of Klingon ships on the station's repair schedule over the Romulan's. It clearly states that Romulan ships were needing repairs by the station and were ultimately assigned O'Brien's repair crew and placement in the docking rings. In addition, Odo voices concern that the Klingons and Romulans were not to use the station for shore leave at the same time. The Romulans were there, despite the lack of effects shots.