The Atlantic Federation seems to be mainly soldiers from the United Kingdom of Edinburgh (Britain) and gear and technology from the United States of Vinland (America). Felt weird that despite being the second most influential member of a military alliance, Edinburgh never contributes more than soldiers and rifles.
So I decided to make my own Edinburgh tanks. While deciding on specifically what tank to base it on, I made sure to distinguish myself from other VC fanartists by staying within the aesthetic rules of VC, mainly using early to mid-war vehicles, so no Pershings, using some layered armor 'scales', and making more physically changes than just slapping on a glowing blue radiator like literally everyone else.
Eventually settled on the Churchill, since it's the iconic tank for the Britbongs during the war. I also picked the M10 Wolverine/Achilles as the second tank, but I don't have any particular reason for doing so other than not liking any of the lighter tanks the British made.
VC artbooks stated that short barrels are preferred, also shows that tanks are usually armed with very large caliber guns, like the Minute tank is armed with a low-velocity 87mm gun instead of something closer to the 75mm M3 gun. As such I decided on a 105mm gun with a (relatively) short barrel for the Churchill and a 110mm gun for the Achilles.