IMHO, more than one NOM does not help. The only advantage to getting multiple NOMS is that is reduces the pool of nominations forwarded (in other words narrows the nominated field). You have to remember there are also SC NOMS and AD NOMS. My DS's Regional Commander advised since he had a SC NOM there was no reason to go out and take a potential MOC NOM from another cadet who was qualified. USMA wants the most available NOMS so that they can properly evaluate and choose the most highly qualified.
In the end, a candidate needs only one NOM, and having multiple NOMS does not effect the selection process, unless it is a Presidential NOM (they usual confer immediate appointment). If you look at your portal it only has NOM checked off, not type or number. Your "application file" that is reviewed by the Admissions Board will indicate the additional NOMS, but if you don't get to that stage no one sees it, and how much weight with the Board it carries is minimal. The Board evaluates candidates based on the WCS, NOT how many NOMS they have.