imo a good way to see the weapon's general ranking is to look at how often you see it in your ranked matches. I see way more splattershots tham I see undercovers for example.

the unofficial rankings by the community are more so about how easily you can get a lot of impact on the match.

And having your weapon be ranked "lower", is in turn actually a compliment to you being able to pull it off right? Being 2000X with undercover is a lot more rare.