Remember, the best penetration performance for an AP projectile is NOT right after it leaves the barrel. Each caliber and model of cannon and corresponding AP round is a bit different, I don't even have to look it up to relay that info.
For instance, the 5.56 NATO will penetrate best at 200 yards. Why? Because at that range the projectile strength and velocity and the moon and the stars are all aligned just right to maximize the best of both. At 50 yards the FMJ shatters too quickly and wont hold together well enough to keep going. At 300 yards the projectile is strong enough but now it is losing velocity (kinetic energy). Sure, we're talking about apples vs oranges when I'm comparing a 5.56mm NATO FMJ rifle projectile vs 37mm to 88mm tank AP rounds, but the concept is the same. At this point, with all of the other things HTC has modeled in to their tank game I'd be willing to bet this is modeled as well. Obviously, it isnt going to matter for some cannons (88mm) but for a 37mm or especially a high velocity 75mm it just might.