Armor Protection Question

[Soldier]

Question for you experts on, armor piercing shells versus armor plating.

Playing Tiger Valley as axis. One of my Tiger (1) PzVIE (early) tanks has fired three shots, at a M3 Grand tank, from 98 meters, give or take a meter. All three shots hit the Grand's small 37mm gun turret.

First shell broke up. Second shell ricochet and the third one achieved only a minor penetration, at a weak point.

The Grants frontal turret armor is 76mm thick and slopes at 47 degrees. The sloping accounts for the second shell ricocheting.

In my novice opinion, each one of the other two hits, should have ripped that small turret right off the tank's hull!?

Were the M3 Grants really this tough?
Namely the turret, built to house such a small gun..