I think this sketch map can be misleading to people walking the Caminho without the intention of going to Fátima. I don't think it gives an accurate depiction of the parts of the Caminho de Santiago that overlap with the Caminho de Fátima. Tomar is not a spur off of the Caminho, it is a town on the Caminho de Santiago and a spur off of the route to Fátima. It's Fátima that is the spur off the Caminho, if that makes sense. My understanding was that the two routes coincide from Lisboa up to a point near Santarém, and then the two split. The Caminho to Fátima heads west, but the Caminho de Santiago from Tomar goes from Santarem to Golega to Alviaizere to Rabacal and then into Coimbra.
I also thought that the two caminhos rejoined south of Coimbra maybe near Ansiao (?). This may be confusing and maybe I have some of it wrong, but I am sure that Tomar is situated directly on the Caminho de Santiago. Maybe you can help clarify, thanks! Laurie