Autodesk provides many templates for use with Revit, but you will get different templates depending on the version of Revit that you purchase and install. While it makes sense that Revit Architecture, Revit Structure, and Revit MEP each have their own project templates specific to their discipline, there is not as much sense as to which family templates are installed with each package.
Some family templates are available in a package that you might not expect, but then not be available in a package that you assume it should be in. An example of this situation is seen in the 3 different Mechanical Equipment family templates. They get installed with Revit Architecture 2012, but do not get installed with Revit MEP 2012. Personally, I would think that the Mechanical Equipment family templates would logically get installed with Revit MEP. It will typically be the Engineer that creates a new Mechanical Equipment family; not the Architect. Another example of the same situation are the Lighting Fixture family templates.
The following PDF shows a matrix of the Imperial templates that are installed with each of the three Revit products.
If you are an Engineer, I encourage you to get a copy of the Revit Architecture family templates for your usage.