The question is whether it is an issue in the first place.
The game is built and balanced around the constant healing, you need a fair amount of coordination or number advantage in order to be able to finish off a target in group environment.
In a 6v6 scenario that means punting away enemy tank(to remove guard), knocking down the target and silencing enemy healer, all at one. And even that does not always guarantee a kill against a good team because you only have few seconds to finish the target before they get protected and healed again.
No matter what you do you can't reach the output of a real DPS class on a non-dps, although some classes can get fairly close(not KotBS).
We have poweful damage-oriented tactics and class mechanics that trade our defences for more damage, the gap between a dps tank (especially a Knight!) and a properly built DPS is gigantic.