You’re very perceptive.
What is your purpose?
What do you plan to do with the info?
Therefore what?
I think a more useful criteria would be, what percentage go more than 50 posts; 75 posts; 100 posts; 150 posts. & 200 posts of what topics.
RC’s tend to post a lot of . . . pontificating blather with very long initial article posts. Some of their stalwarts may mutually ooooo and aaahhhhh for several posts but usually such threads die an early death.
Proddys can sometimes post just as long initial posts . . . and similar things happen unless there’s something somewhat controversial or movingly touching or unusually interesting about the topic . . . then it can go for several hundred.
REPLACEMENTARIANS and us Dispys can go around and around for many hundreds of posts as can the RC’s vs Proddys.
Seemingly, it takes conflict to be dramatically interesting.