If fixing the server speed is the issue why not just make an across the board clock slow down for the game. So every thing gets a hair slower with out making broad changes to existing combat systems.
It just seems to convenient that your lag fix happens to be the 2 characters I hear complaints about. If you want to nerf them like all the other MMO's then just do it. Players are used to it, thats why new games can start up because the older ones start nerfing classes untill the game isn't worth playing.
Thanks for your time