If the City was marked as “Reinforcements” on your map, you will find new ships and potentially additional Tarkhans who may join your fleet.
Hover over a Dollar sign to see the details of the ship for sale, and click to seal the deal.
If you find an icon of a Tarkhan’s head, you can try to recruit them (and their vessel) at no cost. They may also become an Ally that you can call on via your Intercom.
Tarkhans may provide hints to locations of other Tarkhans, or you may learn about them from intercepted intel. It is very important to track down these potential allies to expand your fleet.