According to the Rambam, it is forbidden to argue with the greatest Dayan once he states his opinion. Therefore, in Dinei Nifashos, we only hear his opinion last so that others can state their own opinion.
However, in DINEI MIMONOS, what happens since we do hear the greatest Dayan's opinion first?
In other words, how is someone allowed to argue with him in DINEI MIMONOS?
[Here is the RAMBAM in question]
