Honestly I don't think Red and Satoshi("Ash") are the exact same person,Red is his manga and video game counterpart they do have rather similar personalities as well as quite similar Pokemon like a trusted companion in a Pikachu..and their outfits (well Kanto related anyway) are rather similar..but Satoshi and Red are not the same people..just based off each other or "counterparts" of eachother in different Pokemon related media.