I see this becoming a huge problem to be honest, if you earn those stones by winning and not just by taking part, people are not going to do it. Because its simple, pay to win. All the people/players who have spent $$$, and are sitting in +10 across the board have an easy button access to all these items. This basically could be just another hidden reward to keep these players content whilst the rest has to scrape by.
And on the other side of the coin, if you get stones either way ~ you'll end up getting a WoW clone of the arena, meaning one side will just sit there, die collect stones rinse and repeat.
Given the way the arena is now with no level tiers or teams it really depends on who gets the better team comp.
i won with a level 35 thief and engi on my team (i'm 55/45 illu) vs 3 55s (ma/bard/hunter).
slept them, dots, thief stun when they wake up and pick them off 1 at a time