You can win stacking AP or Arpen but my general rule of thumb if people ask:
Do you plan to arena seriously in an attempt to get a title?
If YES, stack resil and AP, up to and including going full wrathful and switching trinkets to stuff like DV.
If NO, and you plan to arena half-heartedly or rbg often, go arpen to 95+%(use t10HC helm, offset, full arp gems) and be a glass cannon
Again, it's not impossible to play high level arena(at least here) while being a glass cannon, especially if your partner is quality, it's just easier to be more prepared for a variety of comps if you stick to resil/AP if you're going to be less of a bg hero and more of an arena player.