There are a number of factors that go into reviewing nomination slates, but the short answer is yes, for the most part .... Which is why we advise students to seek all sources of nomination for which they are eligible. Essentially, you are competing for an offer to USNA against others with the same nomination as you, if that makes sense.
However, this should not be confused with the admissions board review. The admissions board conducts their evaluation of each individual record based on its own merit of what is submitted in the application (i.e. grades, recommendation letters, candidate fitness assessment, etc.) and has no bearing on the slate review process.