The whole "Strategic Operations Officer" thing never made sense to me. It was very obviously a BS job just invented to have something to give Worf to do on the station - hell, they even made a joke about how pointless it was in the show. What would have made perfect sense to me would be if Worf was promoted and brought to DS9 as the permanent Captain of the Defiant. It's not unusual in the real world for lower ranked officers to command smaller ships - a Lieutenant Commander commanding a Frigate for instance. And the Defiant is perfect for Worf. And hell, he was tactical officer on the flagship for like eight years or more, it's time for promotion! The only downside is that the writers obviously wanted to have the Defiant be Sisko's personal pet Starship. It makes no sense that he would keep abandoning his post as station commander for long periods to fly around in the Defiant, but it's what the writers wanted. Hell, it made even less sense that they put Kira in there as second officer - unlike DS9 the Defiant was a purely Starfleet ship, she should never have had anything to do with it. So I'd have put Worf in as Defiant and then have Sisko come along sometimes as a mission commander - kind of like how Admiral Jameson commanded the hostage mission but Picard the ship in Too Short a Season.