This has nothing to do with any factory specs or tolerances. These drawings are not draw the way they should have been drawn. Let say this was a hobbyist or something...
I will show you a few exemples why ASUS are amateurs! I'm using Solidworks 2015, this is a professional CAD drawing program. When you upload the ''custom nameplate'' you have no name in it. So its a clean surface where everybody can put a name on it without any problems.
When I open the file this is my front view (first picture). So I have to go to the bottom view to see the front of the custom nameplate (second picture). I put a name in it, but I have no idea if this is done correctly. Why? Because I can turn the custom nameplate 180 degrees! So how do I know that the name is not going to be upside down when I mount it?! There is no information about this, only a small picture where I downloaded the files from.
If the draftsman is already in the fault with not showing correctly the front, then I can not know/trust that the left/right/bottom/top is also correct.
Example 2
This is the M.2 fan holder(short). I had to assembly the 2 parts and I also gave them different colours so you can understand my story.
The M.2 fan holder(short) is being showed correctly with the front showing the front, there are no edges that protrude so this is good!
I go the the backview and there you can already tell the difference, the bleu part is not inline with the black part. The edges protrude.
Oké... I can already hear a few guys thinking. What does it matter?! Well, a good draftsman is consistent in his way of drawing. So If you follow the edges of the part you are going to apply this everywhere! But now there are a few lines that not match up with the other part. There is no reason for the draftsman to deviate from the original plan and do it differently on these small pieces.
This is how it should have looked. The 2 parts fit perfectly together without any edge proturde.