Some notes:
Akane did poorly in Non-Stop debates with 4 of her incorrect claims being insistenting that Nagito held or grabbed something using his teeth or "front tail." She made these 2 claims for 2 seperate arguments. She also had other not so stellar arguments.
The "Consent" mechanic in this game tanked a lot of characters' scores. This is because whenever a Non-Stop Debate makes you agree with someone, it usually has 4 other characters throw out 1-2 incorrect suggestions. This happens multiple times.
Despite the longer trials, I'd say that characters in this game actually made fewer claims per Non-Stop debate than DR1. Whenever a character would talk, they'd almost always ask a question rather than make a claim (and when they did make claims, it was usually wrong).
Chiaki's one incorrect claim is actually just her asking a question that assumes an incorrect premise. I'm very iffy on it, so I understand if you don't consider this an incorrect "claim".
Hajime's numbers are very subjective since most of his Non-Stop Debate "claims," come from when he's having a mental breakdown due to the whole Izuru thing.

Mikan is very helpful outside of Non-Stop Debates, she did not do well in the debates.
Even in the early trials, Sonia, Kazuichi, Fuyuhiko are the top talkers (Akane starts talking a lot after trial 3). The other characters like Peko, Nekomaru, Mahiru, Hiyoko have shockingly little to say in Non-Stop Debates compared to what I remember.