I agree with you both actually! This edges into headcanon territory, but I think the Regent cultivated the Envoy's reputation and then when Shen Wei woke up, he convinced Shen Wei that the people's fear of the Envoy is crucial to preserving the peace. I don't think it would be hard to convince Shen Wei who has woken up in a world completely different from the one he knows, and who already had quite the rep before the dirt nap.