Even if all governments were actually formed in the way that this theory suggests, would this fact lend any further plausibility to the theory? Do the origins of a government matter in deciding...

Even if all governments were actually formed in the way that this theory suggests, would this fact lend any further plausibility to the theory? Do the origins of a government matter in deciding whether it is legitimate today? Couldn’t a government have been imposed on its people hundreds of years ago in an illegitimate way, and couldn’t its present-day citizens still consider it a legitimate government in its present form?