30 Vit points = 450 HP... bump that up to 665~HP with defiance active. If you go through a fight without being under 665HP, you have 30 wasted VIT points.
30 Str points... some damage (minor), some mitigation (0~1% through parry), some enmity generation (shouldn't matter)

All in all, it is EASIER to go 30 Vit. Then you rock Darklight/Myth/Allagn accessories for tanking, and HQ melded with offensive stats when you don't need the HP boost.
The *extra* boost you get from 30 Str + HQ offensive accessories isn't going to make a huge difference in a DPS check unless you out gear the content anyway.

That being said I don't bring my War for top-tier end game content (Ultima / Turn 1 / Turn 2 / Crystal Tower ... HM primals) so I went 30 STR and have no problems with it it just makes mid-range/easy content easier. If I was going to attempt turn 4/5 tanking I would reallocate my points and "turtle up".