No. Pet Discordance does not work against players. Player Discordance does, but that only temporarily removes the Skill Bonus from +Skill Gear for up to 6 seconds. I've seen PvP Tamers at Yew Gate relying on +Taming/Lore Jewelry to control their pet, have their pet go wild on them after being repeatedly Discorded and stupidly trying to command their pet. Between that and Masteries being Real Skill based, i always advocate 120 Taming/120 Lore real.
Phantoms in Despise work even better than Satyrs in Twisted Weald. Can get a Phantom, level it up to Lvl 15, and it'll have around 150-158 Discord skill.