Thank you BOTH for the corrections. I have not yet, personally used a train to start a Camino at some of these points, so I cannot speak with the same authority.
I do know from experience at Tui and Sarria about the excellent train connections from farther away points. Recently, I was also told by a reliable source about train service to Ourense and Montforte de Lemos being on the train line that services Santiago de Compostela..
But, I suppose great train service is in the eye of the intended user. I am guessing that it is of most significance to an intending pilgrim who is coming from a small town or village elsewhere in Spain to get to their starting point as quickly and efficiently as possible.
So, the list of "well-served" starting places would likely be those with good train or bus arrivals from elsewhere in Spain on a Friday evening or Saturday morning. By definition, I INCLUDE trains and buses stopping at these starting places on the way TO Santiago, not FROM Santiago.
I suggest that intending pilgrims are less likely to go to Santiago only to turn around and leave to go onward. Many of us who fly to Europe from around the world will do this as a matter of course, as we are used to going out of our way.
I suspect, and admit if I am incorrect, that local folks are less likely to go out of their way to start their Camino. Thus, they would seek to travel from far points TO Sarria and Tui, without first passing through their destination.
I could be wrong. Again, I am not an expert on the Spanish rail system. Plus, we all know how patchy the bus network is. It is comprehensive, but several companies usually share a territory, and the service is not coordinated.
Again, this is a discussion, not a Gospel...