Terminals on studs: Four and no more

I agree Salvo. The edge of the lug (terminal) may not make a major contact with the stud. The lug hole is sized for the size of the stud before the threads are cut. Cutting the threads reduces the size of the stud slightly.
Corrosion can also build up between a lug (terminal) and the stud. This is when it is good to use electrical grease to reduce the rate of corrosion.
Of course, what happens when someone uses a 3/8 inch ring terminal on a 1/4 stud? Even less contact!