If SE aren't willing to remain impartial, are uncommitted to enforcing that impartiality, or aren't technologically competent enough to set up a discrete voting website for similar events within the finalfantasyxiv.com domain, they probably shouldn't bother with more competitions in future.
Saying, "show us your creativity" then picking a minuscule fraction of finalists (the approximate 1% mentioned above) from the massive pool of entries, displaying a significant degree of homogeneity, is only going to show that your grading system is flawed or that the examiners themselves are biased by their own tastes; and that will piss people off either way.