How he met up with Stratton:

Daron Cutler desperately has a need to feel important and useful. He had been involve in scandals and affairs that made legitimate jobs hard to get. The first pirate group he joined up with were some rotten bastards, who crossed paths with Stratton on a ruined moon, both responding to a weak signal beacon from a downed merchant vessel. No survivors were on the ship, leaving the spoils to be had. Stratton proposed a split of the spoils, so both groups could leave alive and peacefully. Cutler's then Captain, Mr. Hatfield, declined. Hatfield told Stratton to prepare himself for his maker the next time they met on that moon.

Cutler decided that he enjoyed Stratton's style more, he had some class and diplomacy. Hatfield was just a killer. Sure, he could manipulate Hatfield, but the man went off at the sight of blood so quick that he was hard to predict. Daron switched sides and helped Jace shoot down his former crew.