I definitely see one side being a Fighter, but the plan is for the other side to be a Rogue or Pathfinder Ninja. The reason is simple, precision damage dealers don't gain much from criticals, but those that use two weapon fighting with high critical range, get them mathematically more often.
Even just Butterfly Sting allows you to pass them on to someone who can use them, while Seize the Moment allows you to benefit from a AoO, which could be, indeed is likely to be, a sneak attack.