If the Cromwell were to be added, what German armored vehicle could be a good counterpart to it?

You don’t, that’s the neat thing. You wait for them to make a mistake, then you shoot, or you use your superior speed to escape while angling, flank them and kill them when they least expect it.

Enemy can also wait for you to make a mistake.

This is not WT, flanking is basically nonexistence in this game due to grey zone camping.