Are these three sentences worded in the correct way?

Following the battle, Szass Tam decided to leave a garrison to defend the Keep of Sorrows while the majority of his forces withdrew back into northern Thay in order to rebuild their strength and make new plans. Meanwhile, Tammith realized that the Spellplague had eliminated the enchantments that magically compelled her obedience to Szass Tam and his necromancers, and she soon decided to desert the undead wizard’s army. As Tammith was leaving the Keep of Sorrows, she was attacked by Tsagoth, a blood fiend loyal to Szass Tam, but she managed to wound the undead demon and escape.