[mac5732]

How about random natives, give some or all of the native races some special tech that they either start with or have capability of reaching. However, in order to obtain it you must either capture or have them join you. Then, you have the Tech only from that one planet, if for ship you can only put on ship built at that planet and you only have it so long as you control planet, if you lose planet for whatever reason, you lose tech until recaptured. This would or could make them much more important to control or fight over. just an idea Mac5732