STR is fine, but you have to be aware of the fight and the group. Shiva is a fight in which your extra STR probably will not do a whole lot. Since you will be mainly focusing on not dying and tanks swapping and positioning, ect. Your DPS uptime is limited.

But anyone who doesnt understand the value of STR and what it brings to the group on WAR is misinformed. Pure VIT is not the answer. I do Shiva in full STR gear, except shiva tank bracelet since it dropped and is an upgrade. 15/15 for spec too.