I think this the Capcom vs SNK tournament disc you are referring to? (See attachment)
But thanks for sharing all the new info!! I had no idea about the Naruto 4 tournament disc, would love to have a copy of that, probably my favorite fighting game of all time
Edit: found the Capcom vs SNK 2 disc for sale on Mercari JP just now for any collectors interested! https://jp.mercari.com/item/m49380552008