You're right about copy/paste disease, it's really difficult in practice and has made ongoing research incredibly difficult. I know most (all?) sites copied the very early research I did to track down Naomi (and every other system for that matter) games, where a lot of the information came from Japanese distributor "for sale" lists (among other sources).
These were normally accurate, but sometimes listed games which never made it to market or in some cases were hilariously mistranslated by me (Rhinoceros Bar Command etc.), but in my defense there was actually a game called "Armadillo Racing" so all bets were off.
I think my "hit to miss" ratio was pretty good tho', I've only had to delete 1 or 2 games so far
System 16 - The Arcade Museum