Applying the God principle to this, there should never be merge conflicts. I should get notified that the file has changed before I even change it. That is how I imagine it would be if a God made it.
But at the time you modify it, the other file may not be modified. And, when your merge partner modifies it, she may be on an 18 flight to the South Pole with no internet access.
Now, sure, you can say "well, God can get around that", but, unfortunately, there are real constraints that cannot be gotten around. Good design is how you deal with those constraints.
