Crusader AA

The Crusader AA was a variant of the Crusader Cruiser tank from WWII. The the MkII is the variant that saw combat equipped with Oerlikon 20mm autocannons.

IRL

The Crusader tank has its own page, so we don't really need to ramble on too much. However, this particular variant of the Crusader is what happens when you combine the Dakka of an Ork to a practical design. See, the Bongs had some particularly painful memories of the JU-87 Stuka, which tended to violently eviscerate whatever they happened to attack. Therefore, allied command decided that significant amounts of AA fire needed to be present in order to make sure that if they lost a tank/transport truck, at least they could take down a couple planes with them.

Thankfully, the USAF made sure that the Luftwaffe was crippled by the time of D-day, making vehicles like the M19, M16, and Crusader AA somewhat unneeded. However, the rapid rate of fire meant that the Crusader was a valuable assault vehicle that could eviscerate infantry with Twin 20mm autocannons. It also was kept at headquarters to provide protection for important asshats like Bernard Montgomery.