Heavier vehicles had to worry a lot about being glanced because the high-strength weaponry doesn't exist in the abundance required to reliably penetrate. A S8 AP1 weapon could actually wreck an AV14 vehicle with one shot, given some lucky rolls. Glances are still dangerous but in a different way. Where before, the enemy needed more glances (Lets see a show of hands, who here wrecked a monolith/land raider with 4 glances? No one?) each glance was individually much more dangerous as it could immobilize the vehicle, blow a weapon off, or stop the vehicle from shooting or moving for a turn. Stunlocking a heavy vehicle was one of the best ways to make it less effective, now thats much more difficult.