So a 1 of 20 in an F squadron would be better looking than a 10 of 20 in an E squadron, regardless of what collateral duties they held? I think that I do have some incorrect preconceptions. Thanks for responding
(Navy) Fitrep rankings vs collateral duties can be a chicken-and-the-egg deal. If your command really likes the work you do, then you are more likely to get assigned more difficult and prestigious collateral duties, which then give you a much better chance at getting a better fitrep ranking... not always, but that's usually how it works.
As far as what the promotion board care most about on fitreps, there are two big things:
One is your average (think of that like a GPA) compared to the average of all of the fitreps that your CO wrote in that "competitive category." For what you're asking, the means all of the pilots and NFOs of the same rank in the same squadron all get grouped together, but LDOs (for example) are in a separate category. This "reporting senior's average" cancels out the effects of easy graders and hard graders (kinda like how NSS is intended, if that helps make sense).
The other is the very first and very last bullets. These always sound positive and glowing, but things like "MY #1 OF 20 HIGHLY COMPETITIVE LTS!!/LT SO-IN-SO HAS MY STRONGEST POSSIBLE RECOMMENDATION FOR [hugely important career milestone]," those bullets mean a lot, while something like "Absolutely has command potential" is faint, damning praise.
All those other bullets about your awesome quals and flight hours, number of bad guys killed, how the job you did on the big inspection made it so your squadron beat all of the other squadrons... all those bullets that guys spend so much time and effort to write... uh, they're, um... important... sure... yup. But you still gotta write them because you can't just put crap there or write nothing at all.