Well, I don't think is always the first who posted the one that takes the first place. I remember I got first place in a Tournament after getting the same score as another player and kept it for a while until somebody dropped the mark. That player had a 28, I think and I posted another 28 and was in the first place for some days until someone got a 27 and then I was second as everybody else with the same score. I do remember I posted after somebody and they gave me the first place. I think I saw the same in the NKF when someone posted a 51 before suncity28 (I am not so sure about this one though) But sure you may know better as you play those tournaments more often. What WGT takes into account for awarding first place is a mystery to me yet.
That's because the scorecards were not identical and other tiebreaker are used in that case (see tournament rules). For example, on a 9-holes, player A post a score of -8 (birdie the first 8 holes and par the last hole); player B post also a score of -8 (par the first hole and birdie the last 8 holes). They have the same score but not the same scorecard. In this example, whenever the two scores are posted, player B will be ranked ahead of player A.
Now if both players have an identical scorecard (for example they birdie all the 9 holes), then the player who first posted the score will be ranked ahead of the other. This post is about this last issue.
Personally, I also think that (all) tiebreaker should be related to the game play (but don't care much for the moment). Even the tiebreaker used when we have identical scores but different scorecards have no much sense. If two players play a 18-holes, player A has a score of 27+30 = 57 and another has a score of 30+27 = 57, the second player is ranked ahead of the first. I don't see any good reason for this. Why the back 9 is more important than the front 9? But I agree that the tiebreaker used when we have two identical scorecards has even less sense :) .