NAPLEX pass rates dont mean anything unless they are far outside the normal bands for pass rates.
1) The Game is Rigged - Some schools teach to the NAPLEX, which means that they have an innate advantage with passing the board exam, but that doesn't mean anything because any student afraid of failing the NAPLEX before starting pharmacy school probably needs to reconsider their desired profession.
2) But the Field Is Still Even - The ACPE requires a certain standardization of curriculum which means that one school's curriculum with respect to the NAPLEX is as good as anothers'. Of course there are variations in curricula that make some schools better than others with regards to where one seeks to go with their career within pharmacy, but thats not relevant to the relationship with the NAPLEX.
So the difference is really the students that a school selected in any given year. Since the average across the nation is some 96% passing, then almost everyone passes. If you are seriously worried you you would be 1 in the 25, you need to reconsider your desired profession. You should only be worried if the school you are attending has a NAPLEX pass rate which is so far outside the normal bands for passing... something which I estimate would be less than 85%.