In chapter 31, Hezekiah tells Ryan one of the slaves is an informant for the owner.
Why do you think a slave might "spy" on other slaves for their owner?

in my opinion i think it was not excessive at all. the maids turned against the queen in his absence, how could he ever trust them again? if he let them go they would surely spread the news of the suitor's deaths, which is much too risky. as for the suitors, they were selfish, rude, and greedy. the god's had apparently marked them for death, meaning odysseus made their death come faster.

the answer is:

to persuade readers that a conquering prince must destroy a former republic if he hopes to hold it.

in the excerpt from "the prince," the author niccolò machiavelli suggests that to take possession of a city and endure the control over it, it is necessary to destroy it first. otherwise, people who have known freedom will eventually turn against the new rulers and fight back to recover their power.