If yer shamans are in melee range its easier for them to pull aggro if there further away they can do more damage before they pull aggro.

I think having reckoning as yeh level is better, although I got both (reckoning and spell warding) getting improve judgement isnt all that great

It helps a ton getting Enchant Weapon - Major Spellpower on what ever weapon he has, even if the weapon is real low level having that helps allot more then having a weapon of equal level to yer pali. hope that made sense :P

Don't start off with chain lighting.

When yeh pull make sure everything hitting the pali before yeh start dpsing

usually the way I start off is gather the critters, park the pali, consecrate, pick one target, hit assist (but dont start attacking yet) cast Seal of the Crusader, judge,
Seal of Righteousness, consecrate, then start dpsing the palis target. Once all targets get hit by at least 2 consecrates I start aoeing (chain lighting, Searing Totem...)