I don't get where you're getting all this at all because it's not even close to any class, it's DPS was akin to a BLM at that ilvl which at that time we didn't have the power creep like we have today where they changed everything (casters having Raging Strikes was a big change). As for White Wind it's a blessing and a curse, yeah it heals more than most healing abilities but at a cost, it has no HoTs, it has nothing smooth out damage unless you cross role Addle and Apoc but it doesn't have Benediction, it doesn't have shields, no snap healing/threat, it doesn't give buffs, it has no LB for DPS or healing, not to mention White Wind is hard on the aggro if you spam it specially in tank stance.
And since we bring up it's "OP tank stance" it's really not that OP you're wearing cloth with the dmg reduction so its not really that great nor do you have tank CDs behind Diamondback which can be cancelled in any Trial by the bosses auto attacking you out of it, oops. It has no CDs outside of that besides it's Rams Breath that can freeze things and without Bad Breath and the dmg reduction BLU would be even more worthless as a tank than it already is it's really not that strong at anything really, tanking, healing, DPS I'd rather just roll with a BLM/WHM that can just AoE everything down faster than a BLU could ever offer + a caster LB ontop of that.
You should really take a more careful look at what BLU really is instead of spouting that BLU is truly OP when it really isn't it's a gimmick that back in 50 when the game was much different than it is today FFXIV has changed a lot and real classes just outperform BLU because that's what BLU isn't, a real class.