I grant the point. Yes. If Norrington had done as Jack said, then things would probably have turned out okay.

I'm not so sure about that. As I understand it, Jack's plan was that the pirates would row out to the Dauntless, and the Navy would be prepared and blow them to pieces. They'd still be alive, but alive and in pieces, which makes fighting difficult, and Jack and Will would have plenty of time to undo the curse.

Norrington leaving the ship spoils that plan, but so does the pirates walking up to the ship instead of rowing - the Navy boys don't notice them until it's already too late to blow them into pieces.