What does penetration of armor matter? The only relevant aspect of anti-tank warfare nowadays is mobility kills. Strafe the vehicle from the side, destroy its t

What does penetration of armor matter? The only relevant aspect of anti-tank warfare nowadays is mobility kills. Strafe the vehicle from the side, destroy its tracks and its just a big obstacle to the enemy now. There was an incident in which a mobility kill was scored against an M1. Crew was unharmed and was able to retreat thanks to the other tank covering it. The tank was ordered abandoned and destroyed. The problem was, even firing at it from the other M1 they weren't able to destroy it.