Draw in AEC(or 2) into Raketen and shreck trap, maybe some mines.
JLI his sniper.
ISG his MG.
build puma to counter AEC.
Try to get schwere flak base before they can destroy it while it's building.
IDEK.
Everything I can think of is easily countered by the sniper+ AEC play, as the AEC can take on all infantry and vehicles you can throw at it in the early-mid game, and the sniper removes all emplacement infantry and MG's. If he can construct the mortar emplacement that's the nail in your coffin. The meta is strong in the Brits now.
