Are these sentences worded properly?

After the Council of Zulkirs’s armies that advanced north from Zolum divided to undertake their different missions, Bareris, Tammith, the Griffon Legion, and a contingent of wizards and priests of Kossuth made their way to Xingax’s hidden manufactory without being detected by Szass Tam’s followers. They used deceit in order to enter the fortress, and then immediately engaged the stronghold’s small garrison of Red Wizards of Necromancy, living soldiers, and undead entities, including an enormous lizard-like monstrosity.