Imagine if Edwin put more thought into his rebellion. Sure, he was angry, but what was he hoping to accomplish? One ship, even as big and powerful as that dreadnought, wouldn't do much to Stormwind, who presumably had a fleet of its own.
Defias screwing over common people made little sense... yet, it hurt Stormwind a little, but made him pretty similar to the nobles who kicked Stonemasons out of Stormwind.
He had vast collections, all over the kingdom, between nobles, with goblins, with savages like gnolls. He certainly had organisation talent. He had friends among Stormwind intelligence service.
If he used the manpower to do what his daughter did years later... if he talked to the people of Westfall, Redridge, Duskwood, who were abandoned by Stormwind... he could've turn his rebellion into a revolution.
Stormwind wronged Stonemasons just as it wronged the people in the country. No protection, gnolls stalked the fields, kobolds took over the mines, murlocs plagued the coasts. When the droughts came, did Stormwind lowered the taxes or tried to do anything to help? I doubt it. Edwin could've pointed out all that, and explain that the people didn't needed Stormwind... Stormwind needed them!
He could've turned Defias into army protecting the country when Stormwind's army failed... like Night Watch, like People's Militia. He could've set deals with goblins, to sell the resources for fair price... all right, better price than what they would've gotten from SW....maybe... He could've built infrastructure and defenses. And he could've turned people's anger on their absent king.
Stormwind was to weak to deal with the revolution. Horde would propably support him, to fight proxy war with their main enemy. It would be Independence War all over again... and the countryside would cease being Stormwind's bitch and show is its equal. I thought 'muricans are all over that sort of crap.