Actually, I like the concept.
Think about it. The Tholians are restricted to working a what, 50 or so hex region (their original space and a 2-hex limit around it), and they can only be found in a 100 or so hex region (the 4 hexes out rule).
Also, instead of tracking BPs and stuff for a small race, the requirements are the diversion of players from Alliance accounts. To field a DN, you need a total of 3 Alliance pilots stuck in the Tholian region, and to fly a BCH you need 2 Alliance pilots.
The only rule I'd change (or clearly specify), is that if there is only 1 Tholian online, he is allowed to fly a special ship, as you need a 2-pilot minimum to play a BCH.