[matheist]

Is there any research showing this standard to be fair?

I don't know of any.

Less important if there are overall less multiple name papers, which it seems from the rest of your comment,

Actually, I think multiple authors is far more common than single authors, though I don't know the numbers to back it up. I was responding to a very specific "what-if" scenario of bouncing ideas off someone else, and describing what would happen in that case.