If the TSN ships were tagged as Ximni vessels in the vesselData.xml file (Side=7) then they would use Ximni fighters. If the Ximni fighters are then converted to be shuttles, then everything works out. The only differences I’m aware of would be the post-battle summary screen would list ‘Ximni ships destroyed X’ if a TSN ship got destroyed and if a TSN ship is ever equipped with a jump drive then it would get the combat jump normally available only to Ximni vessels.