Big-ip GTM Base question about Servers and Virtual servers

Hello all! I have a small and easy question about logical way to organizae many virtual servers (services) on my BIG-IP system: I make some GTM wide-ip for my servers with some http, https, etc. services on it. So, I have 2 way to organize each service as a virtual server:

 

• 1'st way add ALL virtual servers belongs to ONE BIG-IP system.
• 2'nd way create server for each server as a "generic host" and create a virtual servers inside. What is best practices, and why? :)

As I know: SERVER - In this case, the server defined in BIG-IP DNS is either a BIG-IP or other 3rd party system responsible for owning one or more virtual server service.