I agree a lot about the commenting. You make good intelligent comments, and just so you know, you were in the 20. And you bring up a good point, I should have discriminated between visibility (number of feeds it's in) and popularity (number of shares). And yes, you should try out alt accounts. For this one though, I unfollowed everyone, left a quick bio to say to ignore it, and logged out forever.
I could go through each post, look at the tags and who shared it, then sum all the followers for both. So technically, yes, but it would take so long, no significant number of data could ve taken in a time frame small enough that it wouldn't change pretty significantly while I did the sum. Nor would I know how to account for overlap. I'm sure there is some sort of code that could do it, basically a web crawler, which are used on lots of social networks, but I couldn't make one.