You've been able to see your opponent's spec (HP/MP levels iirc) before a Rated BG match starts since they were added. Why not arena? I don't see how this 1 thing ruins arena for boxers. People like Shodokan will still do well regardless. People like me will still be stuck ~1800.

Knowing what 5x or 4x+Healer comp your facing before the match starts doesn't limit the DPS that team does against you. It doesn't limit their targeting accuracy. If you can't adjust your strategies on the fly and adapt to win, arena isn't the place for you.