Following the battle experiences in North Africa, there was a need among Churchill tank crews for a better armament in order to support the infantry. Early Churchill tanks were armed with cannons that had relatively lackluster high-explosive capabilities like the 2-pounder and 6-pounder guns. An enterprising REME (Royal Electric and Mechanical Engineers) Captain, Percy Morrell, recognized that there were many M4 Shermans slated to be scrapped with still functioning 75 mm armament. In a bid to upgrade the Churchill tanks for combat, he suggested and proved the feasibility of taking the M34 gun mantlet and 75 mm M3 cannon off the M4 Sherman tanks and installing them onto the turret face of the Churchill tanks. The modified Churchills, mostly Mark IVs, were given top priority with 200 modified with the M4 Sherman mantlet prior to June 1944. The modified tank was designated "NA75" (for North Africa 75 mm) and was sent to the Italian theater to fight, most notably during the assaults against the Gothic Line.

Introduced in Update "Sky Guardians", the Churchill NA75 can be seen as a sidegrade grade of the Churchill III, but with a 75 mm gun and a different turret design. This leads to somewhat lower penetration values compared to what the 6-pounder on the Mk III can provide, but the post-penetration damage on the NA75 is much stronger than what the 6-pounder can deliver. Another minor change to the NA75's benefit is stronger turret front armour due to the usage of the M4 Sherman mantlet in the turret front. However, with the same weight and engine as the Mk III, the Churchill NA75's manoeuverability on the battlefield will be very similar, if not exactly identical.