I joined an alliance for the event, and while most are doing the event, and the alliance overall shows progress I cannot see any others in either Team IM or Team Cap player/alliance list, nor am I seeing any contribution to the round thresholds from anyone but me. I just finished round 1 and all 70k came from me. What gives?
If they already had 20 people join from that alliance before you entered, the 21st (i.e. you) would start a new group.