Do exempts and nonexempts each need their own employee handbooks?

Q: “For organizations with both exempt and nonexempt populations, is it permissible for an employer to have different time off policies for the respective populations? For example, to design an unlimited vacation policy for the exempts and a paid time off policy for the nonexempts? And if yes, would it be advisable to have two different employee handbooks by classification where such policies would be different, or maintain one handbook with the different policies identified by classification?” – Crystal, Minnesota