Why the wavy cam in Master dial locks, anyway?

[Feryll]

As far as I understand it, the only reason that the most common method for cracking Master-like dial padlocks is allowed to work is because of the unique wavy shape of the cam nearest the dial—it enables one to very reliably deduce the third digit of the combination. I know that rigorous security isn't exactly a priority for the Master Lock company, but wouldn't it actually be cheaper and more secure to use three identically machined cams? I assume that there has to be some sort of pragmatic engineering reason for sticking with the starfish cam...

[emptech]

I'm trying to recover the combo for what I think is a 1500 lock. It says "master lock" on the back but no SN. I've tried various techniques and have been able to open the lock by clearing counter-clockwise and figuring out three numbers. I've had no luck by clearing clockwise and going through the sequence to find all three numbers.

The question is, if I know the combo that opens the lock by clearing first counterclockwise, can I derive the actual combo from these numbers? Does my question make sense?

I have a collection of used locks and would like to make them useful.

Jim