EDIT: damnit, didn't see this was an old post. Wish there was a 'delete reply' button, eh...
Valan with and without armor skin makes a huge difference. I alternate Zem and Valan depending on circumstances.
Dina and Alice come from guild shop which is the hardest fo farm, and currently the new dailies do not provide any guild coins, so we're stuck with the 100 per week from gw and 1000 per raid completion, which is nowhere close to viable.
Well, Dina now has a farming node in ch13, so I guess, it's very recent so I have no idea what her high-level moveset is or how viable she is, since I've only encountered a few in crucible in 2 whole years.