Quickly set up your base, get your Tech Level to at least three and start building Scorpion Tanks. Activate their Canister Shell Ability. This level also has several aerial Flood units, so it doesn't hurt to back the Scorpions up with several Wolverines (who annihilate anything aerial). There is another Pylon just north (right) from Alpha Team's position, another Pylon can be found between approximately your base and Charlie's location, and the last is roughly between Bravo and Charlie. When all teams are evacuated, you have succeeded.