Having one character with a Stagger Lock weapon, even one that's often a Ravager, should have negligible, even unnoticeable, difference in staggering. Stagger Lock does not affect the raising of the stagger bar in any way, so I have still been able to use Fang as a Ravager and Saboteur with great effectiveness (arguably even more effectiveness than otherwise, since that has a great boost to Magic as well). Stagger Lock only prevents that last hit from causing the stagger effect. I can only remember a couple of instances where an enemy's stagger was delayed at all due to Fang's stagger lock (when fighting the Adamantoises and physical fighters have to run all the way across the screen to attack).