It seems there is no official collective noun for galahs but it is permissible to use one of the few assigned for cockatoos!
Confession time- this is 4 photos of the same bird and he was on the same rock all the time.
Wow, I love what you have done here and if you did not tell me, I would have thought it was four mates sitting together ignoring social distancing rules. Fabulous work :)