This is not a rare situation. I have had it happen a LOT of times to me. What I WISH they would do is hold everyone in the starting zone until the entire match fills. As people hit accept, zone them in as now, but then do not open the gates until all teams are filled. That way everyone gets a fair start. If it does not fill after, say, 10 minutes, then kick everyone out and start over. Or something like that. Maybe they can add things to do while you wait, but I would rather wait an extra 5-10 minutes at the beginning of a match for a fair chance for the rest of the 20-30 minutes of playing, instead of getting roflstomped and unorganized as people fill up from one full alliance.