Ok, Ill tell you what, get a Philips screw that is overseas and one that is ASE and whip out the ole micrometer. You will see the difference. And the same with the screwdriver.
I guarentee that the size is different which in fact DOES help the matter. The tighter the fit the better the tool and use. Its like allen keys. Cheap ones dont fit tight and are not made to high tolerances. Buy a Losi or OFNA set milled from drill bit blanks and you could almost bet that you could remove an allen head that has been stripped out by the cheap set.
I was told by many both at the LHS's and the track that there IS in fact a metric Philips. Maybe not by American Standards, but, there is one none the less. They are both probably just called the same thing, but when you use them side by side, you can easily identify that they are not.
I'm a freak about the right tool for the job and have spent countless dollars just to be at a perfection level. Anal, yes, but educated on the matter just the same.
I assure you that if you were to buy and use these or any other overseas 'metric' type philips head screwdriver that you will know the difference as soon as you use them.
I would not lie my man, its not my style.