Is this small passage worded and structured properly?

FYI- Grguch is the chieftain of Clan Karuck. After the successful attacks against the elves, Clan Karuck and one of the orc priests who had conspired against Obould, Toogwik Tuk, raised an army numbering in the thousands from along the eastern edge of the Kingdom of Many-Arrows. Grguch led the army in a direct attack against the not-quite-finished dwarven wall that protected Mithral Hall’s eastern entrance. Since Alustriel’s wizards had prepared spells intended for the bridge’s construction, they were not prepared to help the dwarves fight off the orc horde that descended upon them during the night.