I'll see your Shilka and raise you a Mark XXXIII Bolo Global Siege Units.
Weight: 32,000 tons
Main Armament: 3 independently-turreted x 200cm Hellbores, 4 X 240cm howitzers
Secondary Armament: sixteen 30cm Hellbore infinite repeaters in two lateral batteries, 10 X 40cm BL mortars, heavy VLS (vertical launch system) missile system
Road/Sprint speed: 105/500 kph