It’s only 7 worms. I think 6 worms would be too short. I’m going to reduce the probability of appearance instead. Changed in v.155.4 
Idea
I can’t turn Pecking Order on or off for specific enemies in a wave. Besides, at least it shows you where the enemies will spawn first.
I don’t want to add special cases just for this wave.
The wave would be too short otherwise.