Genjitsushugisha no Oukokukaizouki - Chapter 27

So… no change of perspective right up until the end, huh. You were given a goal by your predecessor (“take back the land”) and focused on it so exclusively you couldn’t see anything else.
Great trait for a soldier.
Awful trait for a ruler.
What a waste.

Also, seriously? Why deconstruct the whole city?!
That’s an awesome tourist mecca thrown into your lap right there! Better to do a land-swap instead. People who aren’t landowners, you can hire in various other cities and towns to lure them out and disperse them and unify your country faster. Pull loyal people from other places to come to the inconvenient-but-picturesque-and-historical newly conquered area and start the careful reconstruction and reformation. The old citizens who own land, you’ll want to put leashes on anyhow -you can dangle the lure of keeping their places in return for their cooperation with the project, or if they won’t cooperate you take it away from them and hand it over to someone who will: best yet if you can hand it over to a formerly-poor citizen of the same city.
Demote the old nobility and tell them they’re all on probation and will have a chance to earn back titles and power by working with you -and then set them to working on your port city project so they’re invested somewhere else. Make sure the large estates are further broken up and harder to recover by handing control of them over to groups -trade organizations or guilds or the like. Harder for the old owners to get them back if there’s not a single new owner they can target.
Then you aren’t wasting all that old history and construction.