The edge is being able to manage your trades. 2 people both using the same analysis for markets will have drastically different results if one trader employs PRM and the other does not.
Wrong.
The edge is to identify and enter into the winning trades. PRM is simply a function of reducing your losses and maximising your gains. But if your analysis or strategy is poor, no amount of PRM can give you gains. It might help prevent you from blowing up. But it will certainly not give you profits.
You can "manage" your trades. But a losing trade is a losing trade. The "edge" is to identify more/bigger winning trades. And PRM does not identify trades for you.
Another way to think about it. If PRM is indeed an edge. Then you could literally enter the market at random and PRM your way to profits.