Well, maybe the pay was good! XD
In all seriousness, though, even if he was a servant of them, they've been gone a long time IC. Why is he only now moving to restore them instead of moving quicker to when they were extinct? If it were faster that he'd moved, there would likely have been more supporters for him to recruit, but by now any who MIGHT have allied with the 'Clan would have moved on; he'd have almost no supporters by now.