This is only if you are using root rotting method, or full melee method to kill mobs.
You can use your pet as a tank and it's very effective, I know for a fact I did it for many lvls once I got the 49 pet spell.
The 49 pet holds aggro, I learned this from a troll shaman that showed me the ropes in Kelethin killing guards and using levi across the city pulling to a spot high up.
You can pull the Kelethin guards easily and I learned how to kill them efficiently.
Slow them, send pet, he taunts and holds aggro so well I did not have to root the mob. Let the pet beat on them till they are at 85%-90% hps, by then he has aggro like a magnet.
I then put 1-2 dots on the guard, then I nuked over and over with JBB till the guard died. If he starts tot ake off running, you can root if you fear he is heading to guards.
Pet held aggro the entire time. This is why it's important to have a strong pet it definitely makes a difference in holding aggro.
Get a reclaim energy mage focus item, like
http://wiki.project1999.com/Torch_Of_Alna_Quest.
The mob rarely even was on me to interrupt my JBB. Root can be used, but again, I found it rare that I ever had to use it.
I took this strategy to Felwithe guards, and did the same thing.
The only difference is the fights can last longer due to them healing and being paladins. Once they are down to 20%-30% hps or so, I would rush them, slam them to interrupt their healing, and simply nuke with the JBB. They died.
The most important thing obviously is to have slow on them, and with slow the pet or shaman can face tank the guards.
***I did have a fungi tunic, but honestly I seen shamans without a fungi doing the same thing so I know it's not needed to kill Kelethin or Felwithe guards. My shaman was a ogre.