Since they serve in the Mishkan they are held to a higher standard of thougth and certainly behavior. As for the Tamai Mais , such a person can be a tremendous and active member of the community and it can all be for the wrong reasons. Such a person is cut off from the Machaneh Shchinah . The Metsorah has trouble with jealousy, a probable cause of stinginess and lashone horah . Rav Hirsch now ties these three character flaws into the next three topics in the parsha.
First topic is regarding the thief.
Very easy to see the correlation between jealousy and theft. The next topic in the Torah is the Sotah, a women suspect of not controlling her desires. OF course she wasn't alone. There is a man out there with a similar problem. In fact, wherever he may be, he will suffer the same fate as the Sotah , should they be guilty.