The majority of 1 v 1 in WvW that I have encountered are against thieves since they like to gank people. I run GS/ Sword + Shield, and it works for a majority of fights. I usually start out the fight with the sword/board to prepare to block their burst or close the gap to stun/immobilize them in order to 100 blade them to death. I trait Leg Specialist so that your (2) cripples will add additional immobilization. Whenever they go stealth to run away I use the Whirling Attack in whatever direction they were facing. That usually is enough to get them downed.