From the article:
The reliable Sherman tank equips the armoured regiments of most British armoured brigades and divisions. The armoured divisions place their faith in the new Sherman V with its Chrysler multi-bank engine. The armoured brigades make do with the older Sherman I, II, and III.
All of them are equipped with the excellent Sherman Firefly VC armed with a long-barrelled 17 pdr anti-tank gun, ideal for taking out the big German tanks. The Firefly will keep the enemy tanks occupied as your Shermans rush around the flank to finish them off.