Some of these are real stretches involving band names getting swapped around.

The original band called "Judas Priest" broke up entirely. KK Downing, and Ian Hill were in a band called Freight together. Al Atkins of the now-defunct Judas Priest joined Freight, and they decided the now-available name of Judas Priest was cooler. It was not the same band. Furthermore, before their first album was recorded Atkins was replaced with Halford, and Tipton also joined. So I would count Ian Hill, Rob Halford, and Glenn Tipton all as founding members.

Opeth is similar. The first Opeth before Ackerfeldt broke up without recording any albums.