Definitely City of Mist. Have the necro lull undead to split up some spawns, and just root/park if you gotta split a couple live mobs close together.
As for tactics, nothing is probably going to be much more effective than the necro aggro kiting a mob while the pets beat it to death. Can have the shaman aggro kite every 4th one or something if mana gets tight (it shouldnt).
You can pet tank, but you'll spend a lot of energy keeping the mob on the necro pet, and pacting/bonding/feigning is going to probably be less efficient than just aggro-dotting and running in circles, although you'll only get 67% of the Dot DMG, most of your dps will come from pets and ..............
A JBB. Get the Shaman one ASAP. It's going to be the single biggest farming-blues dps boost you're going to be able to buy. If he's an iksar, make a new friend that isn't and have the new friend use the JBB.
Also, as an even lazier option, nab a melee class.. Monk, Warrior, Ranger, Rogue, Bard, Pally, SK, whatever and the XP hit you'll take will be cancelled out by the faster dps, having a dedicated puller, and increased DOT dmg because the mob stays in place (and pets don't get hit.) Necro pact + shammy regen should be enough to keep the melee class up. Bard is a super huge score, since he's king of aggro generation and can even twist in mana/regen songs and split pulls on his own.
Just an added thought, never be afraid to nab a 3rd to make good, safe xp even safer and faster.
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