Re: Why was Sisko assigned to DS9?
The Bajorans were leery enough of what little Starfleet presence was there. The feddies only sent a Commander because a higher-ranked officer might have signaled a new occupation to some of the Bajorans, specifically the jumpy Resistance guys. An Admiral or Captain signifies a permanent presence (and an Admiral a significant one), but a Commander shows enough rank to get things done, while still signifying a temporary/joint command.
Also remember a commander was assigned as the person for the entire DMZ...Of course he goes rogue and joins the marque...
In the Marmalade forest (forest), between the make believe trees, in a cottage cheese cottage! Lives Albie, (Albie,) Albie, (Albie,) Albie the Racist Dragon...