Glade Lord has 4 Attacks (=close combat attacks) but only one shooting attack. So Swiftshiver gives him just 2 shots.
To disrupt ranks you have to have at least 2 ranks of five models in flank or rear at the end of the combat (BRB p52).
Only 3+ armor? My bad, was expecting a little more from the emperor ;)
On average it should be 648 poisoned shots. 648 : 6 = 108 direct wounds 108 : 6 = 18 make it through his armor 18 : 2 = 9 make it through his...
I guess he was talking about the Doomfire Warlocks? The like to run right in the center of the battlefield and 6 dice bubble (boosted) Soulblight...