Right off the bat, I can see that you have Red lines- this means that data is not flowing along that wire. In this case, to fix it, put a Shader to RGB node on each of those Red wires 
Generally, you don’t need 2 shaders to do this, you can very easily mix textures with just one (which will save you computation and render time):
This setup lets you use two image textures and a mask to blend between them. The mask image is the top one- you’ll want this to be black and white.
In your case, you are mixing different shaders, which is totally fine. You just need Shader to RGB nodes, or you can use the Mix Shader node instead of the Mix RGB node