Beyond the Border III
Objective: Establish and maintain a supply line for 3 turns
Recommended Echelon(s): AR/SMG (x2), Dummy (x2)
This map can look pretty intimidating with the very big boy Hydras coming down, but it can essentially be broken down to two things. First, we need to use an echelon that can deal with Typhons to establish the supply line. And second, we need to defend our Command Center. All of the enemies on the map except for the Hydras are set to "Capture HQ" AI, so you'll have a fair few of them coming in.
To start off with, we'll be deploying two combat echelons. One on the Command Center, and one on any of the three Heliports. The rest of the Heliports should have dummy echelons.
For turn one, there's two things to do here: clearing out the Aegises threatening the Command Center and establishing the supply line to the extent possible. With the echelon on your Command Center, clear out the two Aegises, then move to the node directly above your Command Center. We want to take the Heliport the Nemeum is sitting on, as well as the node directly above the Command Center. Use your combat echelon and a dummy echelon for this, preferably one from a side Heliport. Be sure to have a combat echelon on one of the two side Heliports, since we'll concede one to the Military. That's it for this turn.
On turn two, we have more enemies coming in from the sides; this time we need to use our other combat echelon to defend. Take out the Military that are directly around your Command Center. Now we can focus on finishing the rest of the supply line. The dummy and combat echelons we used in the previous turn to capture the Heliport and other node can be used for this. Move that combat echelon up to the Rally Node to clear out the trash there. Bring your dummy echelon up next, and swap with your combat echelon. Nothing should attack you on the Rally Node, but Military units will come in on the other node you need to take.
After you've gotten the supply line up and running, you can move the combat echelon by the Rally Node down to the Heliport to defend there. Things will go through that area and will break the supply line if you don't stop them. Keep up the defense of your Command Center until the Hydras are knocking. The Hydras won't take your Command Center, so once they're right on top of you, retreat your echelons. By turn five, you should have had the supply line long enough to clear the map. Just be sure not to leave any echelons where Hydras can get them, especially if it's on top of the supply line.
Video of me clearing this map