Do they ever make sense?
No, they aren't accurate.
This is one of the things they are working on so hopefully, eventually, it will be fixed and show the real amount of posts but I don't think there is a timeline on when it should be done.
Our total board messages are waaaaaaaaaay off too. I'm hoping they get it fixed soon as we were trying to reach our 650,000 post milestone and it would be fun to see how close we are getting.