Sam is in his sky-scraper looking through the screens in a floor.
There is no personnel operating on each floor, rather every screen was enchanted by Sam.
The low-level spirits will be responsible for watching over the whole city and all of these are like Sam's artifacts and they can contact him directly, but he didn't let them.
Rather, he is planning to perform a huge enchantment to the whole building so that spirit would be responsible for reporting Sam.
It would act as an A.I assistant.
He is planning to do so, but before that, he has to check all the nodal points in the city.
The towers that are acting as nodes are not the only ones that are a part of the formations.