Ok, just a little background I play both a sorcerer and an operative for heals in WZ's.
Its pretty much impossible to kill any decent healer 1v1 and any good healer it will take 1v2-3 to bring him down. Its completely different if I have a guard though. With a guard, it is pretty much impossible for a healer to die unless its 2v3-8 (assuming both tank and healer are decent). Less if opposite team is really good at using stuns/mezz to screw with the healer long enough to focus the tank, but to me this is to be expected.
The issue here has nothing to do with the "operative" class though, a sorcerer will normally out heal an operative in most wz's and has about the same amount of life expentancy even without cloak due to there super bubble.
The problem here is when a secondary healer is added, at this point is where those standstill games occur, where no one can kill anyone. Cross-healing should be addressed and healer should probably get a debuff when healing another healer.
Other then addressing cross healing, I feel the game is pretty balanced when it comes to healing and alot of this frustration is due ot bad DPS. I can't tell you how many times I've been in a situation where no one would die simply because all the DPS were flailing around aimlessly while I'm litterally standing still as an operative looking at the oppoisite factions healer sitting there healing just like I am. I can also tell you that any coordinated team of assasins/conceal operatives can dps down a healer/tank in any situation guard or not. So really.. common guys.