Plastic,
I'm in the same boat as you with regards to pulling the charr. It's no secret that with the new AI, casters follow you for a very long way, one at a time. I always thought this was strange in Nightfall (and probably a bug) but I'm not complaining if a single monk wants to pursue me and go "Rambo" on a party of 8

.
Anyway, I've pulled 3 shaman to the Ascalonian guards at the gate and while they did put up a good fight, they still couldn't overcome the single lvl5 monk/warrior woman. The main problem with the casters (I've pulled chaots and ashens, too) is that they don't "wand" (the NPCs anyway) and solely rely on spells to deal dmg. So anyone attempting this would be wise to pull 4 or more casters to save time. A good thing to note is that when you die (which is quite possible w/ 4+ casters attacking you), most of the time they appear to just stick around until you come and get them again
The only problem I foresee is that 4-5 shaman might be too much healing to overcome, in which case, when you do the initial pull, kill the shaman and pull the other caster instead or look for charr groups w/out the shaman (skip groups w/ 2 shaman, obviously).
In addition, I'll try with a guildie (2 person attempt, maybe it makes a diff.) and ask other LDoA seekers to fill me in on "the trick" of pulling melee Charr. Getting the title in 1-2 months vs. 7+ is pretty significant and worth the research, I'd say. Anyway, good luck and happy hunting.
- Stacy the Ranger
EDIT: Beat me to it, Amish. The pitfalls of being a slow typer :P Good to know it's worked for you though.