At the end of the Dreamworks movie The Road to El Dorado (2000) :
They use a ship full of gold and waste it all in order to stop the Spanish army to attack El Dorado
Why would they do that ? If the goal was :
to destroy two columns
With all the resources El Dorado have (like giant columns for example), why did they have to use that way less convenient plan? Is there a in-movie explanation?