That's a pretty nice guide. They missed out the group policy bit but that's fairly straight forward.
You do not need to install any of the routing and remote access role, just the Network Policy Server.
Also, this is crucial, you need to register the network policy server to read active directory dial-in tab. Right-click NPS (Local), and then click Register server in Active Directory. When the Register Network Policy Server in Active Directory dialog box appears, click OK.