Easy fix : eliminate both cp and non co campaigns,open 3 or 4 new campaigns with a lower maximum players cap and everyone inside would have the same cp (200,300,690..whatever some theorycrafter woulf find the most balanced).create a new cp menu for for your "pvp cp build".
This way we would reduce the lag..and put everyone at equal cp.
As an add d bonus it would probably get some mmo pvp'rs to try/re join the game since the pvp cp grind was gone.