This. My active reading journey has come to this. "Sixteen Ways To Defend A Walled City," by K.J. Parker.

After making several attempts to comprehend old-fashioned siege warfare, through various odd works of fantasy that feature sieges, various books covering historical wars, such as the Punic Wars between Rome and Carthage, and the videos of YouTube channels like "Shadiversity," it's finally come to this. A novel that is completely devoted to a city in a siege.