The British armor is a bit lacking. Firefly is only a bit British. Here's wishing for something truly British, the Cromwell tank.
Mk IV Cromwell tank sheet
Country creator/user: Great Britain
Name: Mark IV Cromwell
Length: 6,35 m
Width: 2,91 m
Weight: 28 000 kg
Maximum speed: 52 km/h
Range: 265 km
Main gun: 75 mm (6 pounds) Mk V ROQF gun
Secondary armament: two 7,92 mm Besa machinguns
Engine: Rolls-Royce Meteor, 600 hp
Consumption: 199 L for 100 km
Crew: 5 (1 tank commander, 1 pilote, 1 co-pilote and gunner, 1 radio operator and loader)
Front shield: 76 mm
Back shield: 20 mm




And here's a great write up plus some neat profiles and 40+ minute long video on the Cromwell!
http://www.tanks-encyclopedia.com/ww2/gb/A27M_Cruiser_MkVIII_Cromwell.php