If you've been in the Arena during Season 5, you probably have noticed a particular change to the way gladiators fight. It can be summarized in a single word: "Damage." In the bygone days of Season 4, drain teams and Mortal Strike debuffs were all but an entry requirement to high ranked play. Without a strategy to reduce or nullify your enemy's healing, you were unlikely to produce sufficient burst DPS to actually kill anyone. A few double-DPS teams managed to thrive, but for the most part, a gladiator's number one priority was shutting down the healer.
That dynamic is all but dead in Season 5. Players output such a high level of damage compared to other players' health that healing is almost a non-factor in most matches. My friends, Ghostcrawler is aware of this dynamic, and is looking into it. (It turns out, Ghostcrawler mostly plays a healer in the Arena.) As stated by the crab himself, the Arena should not simply be about burst damage. (Nor, however, should it be solely about healing or solely about crowd control.)
Of course, Ghostcrawler does admit he has difficulty saying what the long terms plans are going to be. The design team hasn't had enough whiteboard time to say anything with complete honesty. But he also hopes that as more Resilience gear enters the PvP system, the damage might scale down to be more reasonable. (To quote, "It's mostly just math.") Still, there's hope that future teams will include more than just seeing which team can burst down the other first.