Vickers and government factories could not take on the work and it was farmed out to a civilian firm, which lacked experience, designers and draftsmen. It took until 1939 to bring the A12 into production as the "Matilda II" and it had not gone into service when the war began, only having been delivered. When the Matilda was supplied to Army Tank Battalions it was an effective tank in the Battle of France and in the Western Desert Campaign, where it outclassed Italian tanks and was effective against standard Italian and German anti-tank guns from 1940–1941 but was later found to be too slow for the fast tempo that German panzer units could achieve and unable to engage the more powerful German anti-tank guns from long range with high explosive shells. Other tank types Using later terminology, the infantry tank has been compared to a heavy tank, while the cruisers were compared to mediums, lights, or even armoured cars. This comparison can be misleading; late Second World War heavy tanks were intended to have superior anti-tank capabilities, which wasn't a focus of the traditional infantry tank. The infantry tank was different from either the "heavy tank" or "breakthrough tank" concepts, although some pre-war multi-turreted heavy machines such as the Soviet T-35 and the German Neubaufahrzeug (both taking some of their inspiration from the 1926 Vickers A1E1 Independent – an idea which was abandoned by the War Office in the late 1920s for lack of funding), which were similar, and with similar doctrines for their use. The Neubaufahrzeug was considered too slow for Blitzkrieg tactics and fell from favour. German, and to some extent Soviet, wartime doctrine shifted towards faster medium and heavy tanks fighting large multi-tank battles, with the role of the infantry tank in the assault taken by simpler Sturmgeschütz self-propelled gun. An important difference, however, was that heavy tanks were generally very well armed, while infantry tanks were not necessarily better armed than other types. For example, the Soviet 45-ton KV-1 heavy tank and 25-ton British Matilda II infantry tank were deployed at about the same time in 1940. These two models had similar levels of armour protection and mobility, but the KV's 76.2 mm main gun was much larger than the Matilda's 2-pounder (40mm). In British practice, the main armament of the infantry tank went in three phases. The pre-Dunkirk British Army Matilda I had only a