Actually, it wouldn't be that resource intensive. Simply take the starbase model, break it up in XSI and modify the resulting chunks so that you get recognizable debris (you'd probably have to adjust UV mapping as well) and then link those chunks as "specific" debris (which seems to be unused?) in the player .entity file. This way you should get big, recognizable chunks for starbases, different for each faction of course. And since you are only dealing with portions of the original mesh, the actual poly count on screen is smaller.
What would be really cool is to have those pieces burn, spray sparks etc. And it actually could be done, but it would require a separate explosion entry for each starbase.
Anyway, just thinking aloud. 