Honestly at endgame, a PLD has no problems holding aggro in ST. Paladins have always had weak(er) aoe aggro, and frankly a 7-8% increase in Flash's hate gen wont help very much. So STR is not that great.
What I can say with certainty is this:


You want a PLD with 5k+ HP in a group to solo tank HM Garuda. They need that much hp to survive up to 3 simultaneous Slipstreams from the boss+adds. This frees up a slot to add an extra dps to mow everything down.
Next, as a PLD, you pretty much NEED ~5.4-5.5k HP in a group to tank HM Titan. In his last phase, Titan will hit you for 3.5k with an ability, and immediately follow up with a 1k autoattack. Those numbers fluctuate a bit, so 5.5k is considered the safe value for surviving that combo, and having enough of a buffer to get a heal and survive the next hit.
In my FC, we have a PLD in full DL armor, with full DL jewelery, DL kite shield, and Ifrit's Blade. He is at 5.5k in a group with 30 vit.
That is pretty much ALL the farmable gear you can get, to have enough hp for HM Titan. Throw out that 30 vit from allocated stats, and you now need several Mythology pieces to cover that gap. It takes about 1.5 weeks per piece of jewelery, at 8 AK runs per week...

That 30 vit is starting to look pretty good right now.