rainbowdash would go against a direct order to not fight back, saying that it's not against a giant ship, she would get a gun and fly her way to the raiders, she would then open fire on them while in flight, she knows that they might have better equipment than her, she knows she might be captured or killed, but the only thing she cares about is fighting for the kingdom till the end and not surrendering like a coward. her capture might be the final demoralizing blow that would lead to a major lack of defense in canterlot, but that is unknown