OP is right. Panzer tactician is strong. But strong doesn't necessarily mean overpowered or that it requires a change.
If you put a gun on my head and force me to change something i'll just make it so you can't use both smoke and blitzkrieg at the same time.
A shared cooldown would make sense to me. If anything its just dull knowing that the majority of axis armour you encounter is going to start vomiting smoke at some point during the encounter.
If reverse speed existed in this game then I think it would mitigate/negate so many issues. As it stands at the moment, armour gets into trouble and belches smoke while reversing in blitz faster than allied tanks can pursue.