Best not to draw any other conclusions from a merit score.
Then don't. You're the one obsessed with those scores to the point of pushing others around to manipulate them to your liking. If you don't care then just move on. I think most sane users have figured out how to interpret the scores in a way that suits them without drowning Meta in their conjecture.
Is someone with 500 earned merits going to be a better poster than one who has earned 5 merits? No that is not an assumption you can make and I am not even sure if there is a super high probability of that being true either. If that 5 merit poster had earned his 5 from 5 different sources on the alt discussion board and the 500 earned it all on meta from inside the 0.13% then I would not even as a gambling person want to bet on the 500 merits guy
Meaningless without providing those two user IDs. Seems to be based entirely on your allegation that top 200 merits and Meta merits are not indicative of post quality, not to mention the unclear definition of "better poster".
if the decision was made by someone who reviewed all posts against some objective criteria that was proven valuable to the board.
Let me guess. Someone else should do it. And you'll be bitching about them doing it wrong.
The problem is really that the top merit hoarders are hoping somehow to becoming merit sources, DT members and MODs.
Who are these horrible people?