Not necessarily. Who is likely to be the better pilot, the lower ranking gut who flies combat missions all the time or the higher ranked guy who has the authority to keep himself safe most of the time.
The admiral's level may just be an exceptional individual, or, more likely, a flag officer with an elite personal pilot who does the actual flying for him.
To add to that, the talented pilot who took out the first Death Star was low man on the totem pole. He's PS8, what do you imagine his rank was?
I'm gonna go with "hey rookie get me my coffee" as his rank