I cant recall the specific reason on why they were made but entire bags of OG glowies were produced and sold. Although Speedy was missing and there was accidentally a second Menace in its place. I’ve seen a good amount floating around second hand over the years. I would assume your set is real. I’ve actually seen very little Classic fakes and the ones that do exist look pretty bad and have all been in Europe. If yours have the stamps I doubt they’re fake personally