This reminds me of a ruling hand I had about 10 years ago. A pair had a long and complex relay auction to end up in 6S. The person on lead wondered which of his two aces he should try to cash. The answer was neither, the only defence to beat the slam was to lead his singleton trump to his partner's Ace after which partner needed to play another trump. There was misinformation and the person on lead tried to argue that with the proper information he might have led a trump. I was not persuaded, having polled a few appropriate people.