Please make it so Gremlin Menders CAN'T heal each other, sorry but, it's hard enough dealing with 6+ Alpha Wolvers in the third match of an Arena solo and having every little hit you can land on those devilish little Menders mended almost as soon as it's dealt, why they gotta be so hard, especially in T3.
Come on
I used to think that way, until I started using bombs. Alternating Dark Briar Barrage and Ash of Agni will make short work of the situation you describe. T3 is really about bringing the right weapons, and if you limit yourself to one type of weapon or another, you're putting yourself at a severe disadvantage. If you don't have the required weaponry, avoid the corresponding strata or team up with knights who do.
I usually just run around the arena, charge my Archeron and then unleash it onto the gremlin. If solo, a single charge (plus the three explosions) is enough to kill it. You'll need to be quick and do another charge and kill the other before it decides to revive the other one. A close charged Levi/CIV works too but may require 2 charges unless they are close to a wall.
It just makes you have to focus on killing healers first.
Granted, in a lot of cases when you're solo, it's not exactly possible. But that's why you carry all those poison vials with you.
You DID stockpile poison vials, right? :p
But I agree, healers healing each other can basically make some situations unwinnable.