Unity and TFS Merging

I'm trying to come up with a good Unity dev collaboration solution for a company where TFS is used as main version control system. I've setup the Unity projects to create metadata and store all as text. Like mentioned here: http://docs.unity3d.com/Manual/ExternalVersionControlSystemSupport.html

Then I enabled Unity's YAML SmartMerge for .unity and .prefab files in the Visual Studio Options like you can see in the below screenshot. I followed those instructions: http://docs.unity3d.com/Manual/SmartMerge.html

Now I tried all that and made a change in the Scene.unity on PC 1, checked it into TFS. Then a local change in Scene.unity on PC2 and used TFS Get Latest. But instead of merging the changes TFS showed the Resolve Conflicts screen only with the Take Theirs and Keep Mine options but no way to auto merge not even a manual merge option. :( The changes I did for testing where independent game objects and just a changes of their Position.x value in the Unity editor, so complete independent game objects. This should be easy to auto merge. I tried the same setup with SVN and it just worked automatically like expected. Only TFS seems not to trigger the merge at all when Get Latest is used.

Anything else I'm missing with the TFS and VS 2015 setup I'm using?