Conflicting Settings in OSX Server Profile Manager (Groups and Users/Devices)
I found the answer to this question myself accidentially.
Please check this site for a more detailed explanation. There is no single answer to this

Condensed:


  Some settings, such as controlling which items are opened at login, are cumulative because no one particular setting overrides another — any number of items can be opened at login.
  Some settings are inherited from workgroups to the user level or from within nested workgroups. Settings with only one ultimate outcome — such as the position of the Dock onscreen — use an order of priority to override the same setting for different account levels. The prioritization of conflicting preferences to override the same setting also applies for inheritance. The order of inheritance and overriding preferences is



Workgroup (the least specific level)   


Device group   


Device   


User (the most specific level)





For example, a preference set at the workgroup level can’t override the same preference set for the computer group, computer, or user level. In this sense, a preference set for the user always wins when overriding other levels.