These folks will definitely have an advantage in PVP. However, it can be overcome with greater numbers of players and good strategy. On Tuesday night I was playing with a group of Hopesfire regulars some in our guild and many not when we encountered a small team of V10 Aldmeri Dominion players. Yes you read that right, Veteran rank 10 players. DC has 1 or 2 on Hopesfire now also. Anyhow, our group of about 18 took down this team of 4 V10 players that also had about 8 lower level players supporting them. We killed them 3 times in the open field, with a few losses on our side, of course. But we only had two v1 players and the rest of us were non-veteran ranked players. It can be done if you call targets, keep an eye on your flanks, stick together, and use damage increasing skills like Templar's Backlash.
When we attacked a keep that they were defending, though, the advantage of defense gave them too much strength and they repelled us multiple times. However, these guys are not organized nor strongly strategic. They'll use stealth some, sure, but that seems to be the extent of their strategy. With this kind of strength, you don't hit them head on, rather use guerrilla warfare. I'd love to see two raid groups taking every AD resource on the map, initially leaving all the keeps alone: completely wipe out their transit system. Then start each group seiging two different keeps as far away from their respawn area as possible, with camps set down at each seige. That, I think, would work against a group like this, especially if a third group went after scrolls while these two seiges were going on.