The entry angle created by hook causes a ball to deflect less when it hits the pocket. 

The answer is false.  All other things being equal, the angle of deflection is the same.  For example if a straight ball enters the pocket at 17 board the deflection is x degrees.  If a hook enters the pocket at a 4 degree angle the angle of deflection is x+4 degrees. 

So how does a hook decrease deflection.   The answer is the rotational energy that is still being released is what really minimizes deflection on half pocket hits. That is why a big hook that rolls out deflects more than a small hook that still has rotational energy left when it hits the pocket. 

Incidentally this also explains the blow out 7-10 which is usually left when a ball breaks sharply but late.  The ten stands for the same reason you leave a weak 10, and the 7 stands because the ball had enough entry angle to still hit the 5 pin, but had deflected enough that it didn't put the 5 all the way to the 7.