I don't play MMO's normally so there could be a technical term for this but what if there's some sort of feedback/rating system. People give a score or like a thumb up or thumb down (positive or negative) and can add a comment--then when the duty finder finds all the members, you can have a minute or two to review the members and decide whether you want to proceed with that party. That way, you'll know ahead of time whether to do the duty with that person instead of having a "kick" feature.