Intention:
Balance the different perk risk levels taken by attackers and defenders, making it more "fair" and thus increasing the willingness to attack.
Situation:
Right now the risks someone takes when rolling a perked tank are very much different depending on if he is a defender or an attacker. Unlike with perked airplanes, a perked tank driver can hardly hope to get his perks back when spawning to an enemy base for a fight. While theoretically possible, it's rare for a Tiger or Tiger II driver to get the needed separation from enemy forces for a successful landing, especially as sooner or later aircraft will arive. The defender has all advantages: He can sit on pavement all the time, being able to land his perk ride even when turret, engine or tracks are gone. He may even ditch at a discount anywhere near his base when he's about to die (falling bombs), which the attacker can not. The defender also has potentially quicker access to supplies.
All this together means a defender doesn't risks his perks as much as a attacker who basically has to write his perks off the moment he spawns in. That's why highly perked tanks (Sherman, Panther, Tigers) are very likely to be concrete sitters, waiting for inferior unperked tanks to show up. The attacker however is more willing to grab bombs for enemy King Tigers as rolling an KT himself, has his own perk loss is almost guaranteed. Again, in comparison to that a perked plane has much higher hopes to make it back home when bringing the fight to the enemy.
Proposed change:
A reduction in perk costs when spawning into enemy territory. Depending on amount of reduction, some players may even start to up Panthers or Fireflys in an attempt to break a spawn being camped by Tigers.
