A+ for creativity though.
I don't know if that's quite fair. I think it's reasonable to wonder if any cards trashed during the "window" of Noble Brigand's execution would be gained.
Oh I didn't mean it to sound condescending or anything. I just wouldn't have thought about possible Copper junking with Watchtower. It would be kind of neat if it worked that way.
You could also reveal a Beggar, trashing the two Silvers with your Watchtower, then reveal your Diplomat (you still have five cards in hand because they played a Council Room earlier), discarding some Tunnels, trashing the received Golds with Watchtower, and then when the attack rolls around, you reveal a Market Square when your treasure is trashed to get a Gold, then reveal a Trader to get a Silver instead, then reveal your Watchtower to trash it, and then reveal another Market Square to get another Gold, then trash that with your Watchtower, reveal another Market Square, then topdeck that Gold it with your Watchtower.
What happens then?