And how we are supposed to counter that
This Commander is late game focus, so fist thing you can do is gaining advantage in early to mid game, make use of UKF early game weakness.
If the game come to later stage, assuming ukf player can built up an idea formation of a churchill cs, a firefly and an aec command vehicle. With the same amount of resources, you can afford 2 panther and focus down the firefly, or simply go ele/jagtiger to hard counter all of his armor. As okw, you also have the option of spamming jagpanzer and focus the firefly.
If he go for more than 1 churchill or firefly, the remain pop wont allow a large infantry force so you can gain more map control by spread out and avoid fighting head on with his main force.