TPM Darth Maul wasn't a character. He was a glorified prop, like Boba Fett was in TESB and ROTJ.
Both were cool-looking Rorschach inkblots that you could buy crude facsimiles of in department stores, and imagine all sorts of cool backstory for that they never had.
TCW turned Maul into a character, and AOTC turned at least young Boba into a minor one.
As for "Sith apprentice sandwich":