Are these two sentences worded in the best way?

FYI- Szass Tam is the lich/undead wizard and the Council is the mage-lords. When the Council of Zulkirs and the southern army’s other leaders met in the town of Zolum to formulate a new plan of action, Bareris suggested that they launch an aggressive campaign against Szass Tam, since arcane magic being diminished at that time due to the Spellplague weakened the lich and his forces more than it did the other mage-lords’ legions. The zulkirs agreed with Bareris’s idea and decided to swiftly strike and try to gain control of many of the lands that were under the undead wizard’s dominion.