So this is my perspective, of course, but my read on Zhao Yunlan in the book is that he's less nice and more manipulative. He's "nice" to Guo Changchen because he's the nephew of a muckety muck at police HQ and he wants new offices for the team. He's "nice" to various people they interview because it's easier to get things out of them when you're sweet than when you're confrontational -- depending. He doesn't actually care about people too much in the book, with the limited exceptions of his team, Professor Shen, and his family, we learn over the time. But this is something we'll get into more as the episodes progress, but Zhao Yunlan is VERY good at playing the game of social currency, and to me, this in no way translates into sincere kindness.