Thread:Kornigator/@comment-25669516-20160320151902/@comment-25669516-20160324214323

Nah the only Google play integration that SG has are the achievements. Also if you use it as the platform to sign in to the game any change you make in your Gamer ID on Google will be instantly reflected in the game (it is slowly becomung like your Apple ID it seems).

P.S. This may also explain the same named guest thing. One of them is the actual guest and the other probably copied the number and used it as her/his gamer ID which is why they have the same name although they are different people.