Related to How many planets were there in the Empire at the time of A New Hope?

OK, so if there were literally Millions of worlds in the Empire, how many total worlds did the Rebel Alliance control? Is there a canon estimate? (any canon).

Wookiepedia lists 30 of them, but that's just named ones.

Doesn't seem very feasible that Empire would even pay attention to 30 measly worlds and build a frigging Death Star on their behalf ... it's like a country the size of China building a nuke merely to contain a rebellion by 5 small villages.