Re: Why was Sisko assigned to DS9?
The best way to think of it in modern times would be.
You have been assigned to run a port facility for the new government of a small Latin American country coming out of a Civil War. Your not going to insult them with a non-command officer, but a captain or higher wants a better command, a real starbase or ship. So you find a commander that has leadership skills, who going sideways, and send him out to run things and to gain some sort of rapport with the nation. The commander becomes buddies with some of the leaders and is running the port well.
Then oil is found....
In the Marmalade forest (forest), between the make believe trees, in a cottage cheese cottage! Lives Albie, (Albie,) Albie, (Albie,) Albie the Racist Dragon...