healers are to OP in rival wings

[Zeonsilt]

1 healer vs 1 dps should be a stalemate, that's a fair balance. But the content should most certainly not 'reward' a group stacking healers above all else, that's just poor design.

Since you bring up World of Warcraft:

I played WoW at Glad level(Rogue) -> an Arms Warrior could easily kill your healer solo with all damage cooldowns/procs activated and "NO TRINKET" available on your healer. And not only Arms War, but some others classes too. (Lich King/Cataclysm, not sure how it's now in Legion)

If you ignore your healer, he will die sooner or later from 1 good DPS class on him. (top-tier healer Vs. top-tier DPS)
There's a reason why some people played Arms + double healer in 3v3 previously and got something like 2800 rating.

p.s. Blizzard balanced the game around 3v3.

Speaking of balance, i never saw a healer going OOM(out of mana) in FF XIV, is that even possible? This is pretty poor/stupid design too.
In WoW mana management was an important part of PvP, sometimes you need to get out from the battle and drink "water" to regen mana or use some innate abilities (i.e. from Druid) to restore it.