PRX playstyle depends on confidently taking space and winning aim duels with their world class trading,teamplay and mechanics.
While they are really really good at that .The reason they haven't won an international trophy because their playstyle requires them being confident but grand finals can get on their nerves which leads to a sharp drop-off in their performance while other teams can rely on their mid round or experience/out call prx thus giving them an edge.
So if they can keep the same mentality while playing in the grand finals as they do in normal split games they can win it.
Until then prx is not winning anything.