Seems good. But I would add that by the time Eyra reached the tower, the Devoted had dwindled to almost nothing, given that almost 800 years had passed since they'd last been in contact with their Supreme Leader. The remainders would have fought the etruscan expedition with the fury of a bygone age. 

Bringing down the tower is something Eyra would never be able to do, even in her prime, and she was definitely not in it when she reached the desert. Anyway, she would see no reason to. She'd steal everything that wasn't nailed down, ship it to her vault in Analos, and seal off the Tower with a boulder or something.