The windows-10 is supposed to be used for questions related to Windows-10 PC as said it's usage guidance.
Use this tag for questions about connecting your Windows phone to a Windows 10 PC. For questions about running Windows 10 Mobile, please see windows-10-mobile.
10 questions is a large number here as it is about 20% of the total questions in that tag to represent the mobile version of the operating system.
Update : What I am trying to say is I think with the unified windows approach people think it is correct to use windows-10 tag for the mobile OS which is not as it deals with problems of Windows phones with windows 10 desktop OS. I fell that renaming windows-10 to windows-10-pc will end this confusion.
Should we rename this tag to windows-10-pc?