For those strugling with ?-8, put all squads on the top camp. This way they all arrive at the middle at the same time (due to not running further after teleport). This way each squad will end up on one lane. However this does mean each squad has to handle 1 pest. And they are pretty tough on this stage.
I made a special list for this, instead of the lazy auto group I want to from top to bottom and placed my strongest (highest attack) in each slot, as I reach the 4th group, I went to the second column and did the same. This way each party end up at roughly the same attack power. Then I just checked to see if I wanted to swap a few so each party had 1 of each type.
Went with the highest attack power helper squad I could find. Was still a close call, some pests barely went down for me. Good luck to everyone.