I'm planning to build an endurance readout into my damage calculator, but in short: for endurance builds, you want to maximize damage mitigation and healing. Max HP only helps with damage smoothing, which is less valuable when standard heals only heal a small fraction of your max HP. In general, a little more HP isn't going to save you from a wipe, however a little extra damage often DOES save you from a wipe because it allows you to control the Rage meter (either depleting it to avoid a Rage Overdrive, or maxing it to avoid a Normal Overdrive). So for an endurance build, you should aim for -50% ATK DWN and 2 strong healers (~500 HP/turn), perhaps in combination with damage reduction abilities (e.g., DEF UP and/or damage cut).