Grandmaster Sid is truly is a gem. He’s a grandmaster armorer.
The 100 plus armor sets Lorist managed to retrieve from the defeated bandits were actually made by him over the past three years. He’s also well-versed with looking for metal ore veins. The iron mine near the bandit stronghold was found by him. He uses the materials gathered there primarily for making weapons and armor for the bandits.
The Norton Family would desperately need someone like Grandmaster Sid, so they brought him and 10 others within his family to the dominion. He could be considered to be part of their spoils since he was serving the bandits and is subject to whatever they have in mind for him.