Using armored units built at your secondary base in Illange (preferably Sherman tanks), advance northeast and destroy the Bunkers protecting the Nazi base. With the base defenseless, MG Infantry units (preferably from a Barracks you’ve built in Illange) can capture the Nazi Command Center and other buildings. Use the Command Center to produce German Engineer units and build a Radar Station so you can advance this captured base to Tech Level 2. Now you can use German Engineer units to build a Tank Factory and produce Tiger tanks and Wurfrahmen (the Wurfrahmen has a much greater range than your Calliope Shermans). Alternatively, you can simply destroy this German base, which has the advantages of being both easier and quicker.
It’s time to take out the Ammo Depot Sagnier mentioned. Order the group you assembled at your secondary base (the one with the Pershings and all your heroes which probably contributed in the capture or destruction of the eastern Nazi base mentioned above) to advance west across the bridge and then swing north. As you move toward the Ammo Depot in the northeast corner of the map, you’ll see a Tank Factory: take it out now! You’ll meet some stiff resistance, but you should steamroll them fairly easily as long as you remembered to bring Bedford Repair Trucks and use Lynch’s Quick Repair skill to keep the Pershings intact.
You can augment this attack by advancing eastward from your primary base with the Shermans and Priests you’ve produced. And of course you can always use Call-In B-17 Bombers, but if you do so make sure you take out the Flak Bunkers guarding the Ammo Depot. As a finishing touch, use an Engineer unit to erect AT Turrets to block the north-south road used by continuous Nazi reinforcements.
