I can agree with that statement; although Iím not sure why a Federation officer would be on a Cardassian ship. At this point, (post dominion war), the Klingons and the Federation have been allies for some time; and much like other nations who are allied, who often send exchange officers; a Federation officer on a Klingon ship seems more natural for me. I also freely admit however that I love Klingons, so am a little prejudiced towards a Klingon ship.
I suppose, a Cardassian ship, could work; if during the pilot episode they established what with the dominion war over, the Federation was somehow helping the Cardassianís rebuild/the Cardassians asked for help from the Federation. Not sure though, I think they would have to come up with a plausible reason for the Federation officer to be on board
Post Dominion War, I envision Cardassia being like Bajor after the Occupation; massive damage, millions dead, destroyed infrastructure, no economy, etc. The Federation would provide whatever help they could/were asked for. Part of that might also include an officer exchange so that the two vastly different species can begin to understand each other a little better, build relations so that any future bloody conflicts can be avoided.
But that's just things are in my head.