Looking at gen vs noob v3 pictures and comparing the crown guards, i think i found a reason why the crown guards are thicker on noob vs gen.
As you can see in the picture below, the crown positioning on the noob case is more centered to the case, where the gen crown sits a little higher. Noob case creates this square shape in between the crown guards, where gen create more of a trapezoid shape. Hence the noob crown guards look fatter from the front compared to gen. Now i am almost certain, that if we measure the crown guards from the bottom of the case, the noob crown guards would be thinner in respect to gen crown guards.
Noob vs Gen crown height
Noob vs Gen