Been a while since I've revisited this. (Working graveyard shift REALLY messes up my creativity.)
Should I allow more than a single ship? Perhaps a small task force including Romulans and maybe Klingons might be required. If so, The Romulan Commander from Balance of Terror would command one ship and be a moderating influence on the Romulans. Kor and the Ningtao... The Constellation...
Ever notice that many of the same people who want variety in life frown very hard on vanilla... But without Vanilla, Baskin Robbins just wouldn't BE 31 flavors.