I am curious as to what you base this on. Wind, so far, has had absolutely awful F2P Grids, down there with Fire. Meanwhile, Dark has an extremely strong F2P grid, which makes Dark damn strong despite being weakest in the "omg I have every SSR Hime ever!!!" meta. Which is the meta that people keep talking about...
But, for a new player, that doesn't really count. It's not like you're going to get all those Envy Axes and Hammers, because fuck you.