At the outset, to grasp that one in ten thousand miracle, the Mushroom Civilization ruthlessly broadcasted their coordinates to the entire universe.
This meant that civilizations receiving this electromagnetic wave message would definitely not be limited to the Wandering Alliance; any civilization with their receiving equipment switched on would receive it.
Of course, not all civilizations receiving this message would be interested in rescuing a Level Two civilization. Excluding those from vast distances or with inadequate technology, the lowest estimate dictates that there should still be civilizations deciding to come other than the Wandering Alliance.
Thus, in reality, many civilizations had already gathered outside the asteroid belt.
After the Wandering Alliance completely annihilated the Shell Clan Civilization, they hadn't even had the time to clear the battlefield before discovering alien civilizations approaching from outside the asteroid belt.
