Due to the ability to pentameld crafted slaying and fending accessories with VIT and STR, to be the most effective tank with the current meta, you -must- pentameld and use these accessories. Secondary stats are so weak in comparison to strength that using i150 crafted accessories is vastly superior, especially considering using these you gain(with perfect melds) 155 STR for the loss of only 100 VIT. If we considered these stats to be equal(which they are not, STR is better with the insanely high DPS requirement in savage,) this would still be a huge net gain, not even factoring in the negligible difference in HP at these high gear levels. Accessories that are i150 should -never- be considered superior to their i210 counterparts. This doesn't even touch on the gil cost and/or time requirements needed to procure the materia for these accessories(on my server, I've often been quoted 8 figure total costs.)

Due to post lengths, see my suggested fixes in my first reply.