That would at least be better than dropping fflogs like I half expect

Because that's a website that holds logs, the very thing he seems to be against.
Still would require verifying if 1 out of 8 people in a JP only group is on a PC. All it takes is one person parsing and sharing the information with everyone and draw conclusions together.
The overall point of what I wrote though is that one can't just drop a statistic and say "look it up". It's far too easy to get away with that. After all, I did try to look it up, found no such case when I looked up people who had the Achievement "Heart to Heartless" done.
Plus I doubt hardcore content absolutely cannot be cleared without third party tools. But they do help in personal improvement throughout. Just as much as how I doubt people are saying "It cannot be done" in absolute terms either. Just that they likely help, and they do. But what do I know
