Long barreled guns are an upgrade to add firepower to a weapon conceived to exploit breakthroughs and drive deep behind enemy lines. Guderian written that the engine is a weapon that is as much important as the gun in a tank. Tanks are more expensive than assault guns. Thus german doctrine stipulated that tanks should be dealt by assault guns to save tanks for breakthroughs. Of course a tank company can end up fighting armor in a meeting engagement, but it was not their main role. If you are planning to create an strategic reserve, you will strive to avoid meeting engagements against enemy armor because you know that you will sustain losses. Speaking of mastery of maneuver, avoiding unnecessary meeting engagements is a good example. German defensive doctrine in WWII is initially based in WWI prussian doctrine: the elastic defense. As everybody knows, the prussian Heer did not employ tanks in large scale and all their defensive doctrine against enemy armor is based in assault guns and infantry tactics. The tank appeared as a defensive weapon as late as 1943 when Fire Brigades was introduced in german defensive doctrine. Even thought, the Fire Brigade concept is about attempting to fight on favorable terms, hitting and running. That would mean avoiding enemy armor and trying to isolate them from infantry support (crushing enemy infantry). If you want a good example you can analyze Manstein's backhand bow: + Castling ----> Armor strength saved. + Schwerpunkt -----> Against the deep flank of Group Popov (mostly infantry). + Result -----> Soviet armor isolated and destroyed in a 'kessel' (meeting engagement avoided). Manstein's Fire Brigade avoided fighting enemy armor until he was sure he would isolate them. Kursk is a completely opposite scenario: the germans intentionaly set up several meeting engagements against soviet armor. This is why I think it's a doctrinal issue rather than tactical or strategic.