While Vue does prefer .vobs(typically) - since the new version(vue6I) the files sizes tend to TRIPLE in size once converted to .vob- this goes for OBJ/3ds/Pz3's etc etc - I have reported this to tech. 

In addition there is still a memory leak.  What you might could try is using the mil figures as alpha planes or rendering each on a spearate layer - hiding the ones you don;t need & composite in a paint program.