Alright, based on what we know so far (and to be clear: I am still opposed to pursuing the remainder of character claims in his DP), I'd say we have some reasonable options for the theme split. I really don't buy RM's framing of that split, whether it's balance oriented or mental vs physical martial arts, that just doesn't break down as cleanly as he seems to believe it does. Alternatively, I've suggested that it could be geographic. The Asian vs. non-Asian divide that Earth provided might work with this set, but it gets complicated when you include Sambo, a Russian martial art. Defining that as solidly Asian or European seems arbitrary. If it's country-specific, that would depend on how we define the origins of Karate, since they came from the Okinawa archipelago. That could fit with China or Japan, though it was independent at the time so that's not an easy call, though I'd say it goes towards Japan because it was imported to that country first. That would place Aikido and Karate (CN and That2) as scum.
However, as I mentioned earlier, I'm also considering the option that it's common disciplines vs. uncommon disciplines. Karate, Wrestling, Kung Fu, Judo and Sambo are all relatively common disciplines from what I've read. Aikido not so much. It seems much safer than the other claims given so far, and most closely related to Judo, each being a throwing style. Again, this points to ComputerNerd being an outlier.
As for my reads on everyone else (I've already given my reads on the rest), I'm neutral on Earth and Supa. They haven't contributed enough for me to read them. I townread RM and Pie, since they're largely following their town metas and RM's insistence on his theme split just reads very townie to me. Mharman suddenly deciding to give his character claim makes me question the slight townread I had on him up to this point based on the back-and-forth with Incel, which sets him in neutral territory for me right now.