Still getting owned by rng on ?-4 but in case anyones struggling with ?-3 you can use 2 squads, both slow (300~), and a 1 fast one (550+) to clear it. Just put the 2 slow ones in the middle spawn and your fast squad in the bottom one.

I kept having one team go through the bottom top passage with 2 whirlwind nodes and clearling the map before someone got through the webs