tell us 4 ways to do so as brits
1. Use "Designate command vehicle" on a bren carrier. This comes with a free recon plane that flies around for days. Then find a path that cuts through his army to his ISG.
2. Upgrade pyrotechnics on an infantry section. Sneak up on his ISG and lay down a 25lber barrage. Even if you're forced off, this buys you time to repair your mortar pit safely. This is especially effective if he's positioned next to his medic truck.
3. Call in a commando glider. The plane grants some vision and you can again use the commandos to sneak up on his ISG and decrew it.
4. Use your sniper to sneak up and decrew it, or call in a 25 lber barrage.
This has made me think that it may be possible to destroy the ISG outright with PIATS, the .55 cal sniper or the armoured car. I'm going to see if I can get a friend to help me test it later.
Alternatuvely. BUILD A SECOND MORE FORWARD MORTAR PIT SO WHILE HE KILLS YOUR MORTAR PIT #1 YOU CAN GET HIM WITH #2.