I guess when the Dohlar fleet and the Tarot joined together and started their voyage toward Charis, Merlin COULD have had Owl direct some of the incendiary nanobots to the powder storage compartments of every one of the galleys and accompanying support ships. Then, at the appropriate moment when they're passing Armageddon Reef...
Kaboom.
Invading fleet destroyed.
No inconvenient survivors.
No need for the Charisian galleons to head south. They're available to repulse the other fleet (Corisande, Emerald, Chisholm) with far fewer casualties. Perhaps Haarald lives?
As a tactical officer, Merlin SHOULD have thought of that immediately ("If you ain't cheatin, you ain't tryin").
But then I guess the whole plot would be a lot shorter!


Just stirring the pot..