Wasi,
your tank tactic in general is absolutely right.
Local superiority is the key to success.
This ensures, as long as your armoured Kampfgruppen stay strong enough, you keep the initiative.
If your weapons are too weak, like stated above, maneuvering is the key to success: maneuver the enemy out but move a useful AT-gun (50mm) with your fast forces and set it up on a reverse slope with very close LOS to the estimated approach route (max. 100m).
Then your tanks play the bait and when the enemy comes, he's flanked out by the PAK.
If he's a better player, he will also mass his forces and not use single tanks. Then keep your PAK hidden until he passed by with his tanks.
Then he sits in the trap.
This was common german tactics in early russian war and it works in CM, too.