Alright, as a sniper, it's really irritating to see a healer out-heal the stream of dedicated DPS I have directed at him if there is a tank set on guard. But I understand that this is working as it should because it does require teamwork and coordination. As obnoxious as it might be to me at the moment, I also realize that it's because they're doing it right, and I commend them for not being zerglings.

However, I think that I could use some tips on means of dropping a tank/healer duo, not necessarily on my own, but with one of those mythical competent teammates.

First thought I had was: Cover-pulse or other PBAoE knockback to split the pair outside of the 15 M guard range, mezzing the tank, and proceeding to attempt to drop the healer Asap. Tough to set up to use a sniper's cover pulse, but an assassin's overload should do the trick as well as provide that extra DPS 'umph'.

Second idea: Not really practical for a marksman sniper, but AoEing the pair. Hard stun the Healer, but AoE both as much as possible. Since the tank would be taking ~ half of the damage from delivered to the healer via guard, and has probably Taunted you to debuff your damage to anyone else anyways, the tank should be taking at least 120% damage from the AoEs (bonus for internal damage!), meaning that you're trying to kill the tank first by applying additional damage via the guarded Healer. Generally, I would expect the tank to try to remain within guard distance of the Healer, and hopefully the two will be within an AoE Diameter.

Any other ideas on how a duo might break the synergy of a Guarded healer?

The game needs single target knockbacks. The Guard mechanic came across from WAR, where (mainly the Tank classes) had access to single target knockbacks which could be used quite effectively to separate guard bots.

I'd probably give it to the Shadow/Assassin. Guards/Juggs already get 2 leaps, VG/PTs get a charge and a pull but Shadows/Sins only get a pull. Yes they have force speed, but in PvP force speed is inferior to the leap/charge the other tanks get (longer cooldown, doesn't take you straight to the target and doesn't pseudo-CC irrespective of Resolve). The Shadow/Sin knockback would be 45s cooldown, cost around 30force and would knock a target back 35metres. That way a Guard/Jugg or a VG/PT would be unable to instantly leap/charge back in and would actually have to move slightly before they could do so.