A lot of the Soldiery stuff drops Parry for stuff like Crit and SS. I'm not sure if we're being trolled by Squenix, but VIT outweighs everything by a wide margin so given the choice of more VIT and less of some secondary stat, I always choose more VIT.

The other issue with SS is that WAR doesn't have Invigorate and we burn TP down like crazy, in any protracted length fight we are guaranteed to run out of TP unless the boss conveniently leaves the arena for a bit and we can regenerate some. Fortunately, outside of mainly T8, in general this is the case at endgame.