A Cardassian ship might work better as a source of tension between the new XO and the crew, what with the recent war, the hostilities before it and the Cardassian track record of brutality against others.
You could also include a half-Bajoran among the senior staff as well, to look at their life growing up alone and isolated in such a repressive culture.
Commander Austin Harris, First Officer, Deep Space Nine (by FltCpt. Bossco)
8.01 - Darkest Before Dawn
(Chapter 8 added, 12/09/2015)