I noticed this the other day but obviously at the start of the round you can switch between races in the "change empire settings" so in theory that means you could be an attacker and build a few droids, then switch over to banker (with no droids special option) and still have a few droids, just so your one of the only bankers with droids that doesn't have the droids special rule.

Kind of strange seeing a message saying "2 Droids died in the defense of the planet" and they have not even got droids on their race lol.    Would that even work or does the game clear such builds after you have swapped races.