This is already a case, you can't acquire any Gold(although the UI will show up, but won't add any gold to show potential gold that could have been stolen) if there isn't any gold to be taken.That early gold is like a free Carthage UA to me. Early gold is too good it helps m
e rush building, buy units to swallow my neighbor (for more gold).
My proposal is limit the gold gain to the victim's coffer. Its stolen gold, there is nothing to steal when your victim is broke.