On a conventional MBT, if penetrated, which is highly unlikely by a tank round. It almost certainly would be the end, not a lot to stop a sabot bouncing around inside. On older MBTs the turret ring or sides were the weak spot.is a frontal penetration not the end of things full stop?
Modern Panzers have the turret ring recessed into the hull armour, so eliminating the weak spot. Reactive armour on the hull, side skirts and turret also enhances survivability.