I originally did have Hide on the list but removed it intentionally. The Sneak-Thief is going to be the Skillful equivalent of Brawler when I finish it, one of the two primary focuses being "movement."
Combat - Physical power and ability in combat
Skillful - Skills, tricks, and precision damage
Magic - Spells and magic
I was planning to have a few "cross group" archetypes, such as the sniper, but these are intended to be the exception rather than the rule. Sneak attack is definitely something I want to keep set aside just for Skillful classes. I'm also tentatively considering dropping precision damage off of the sniper for a different ability and creating a skirmish damage based archetype that works cross group instead.