I took a bus from Granada to Cordoba. I'm not sure of the status of the train tracks.

I would arrange the order of cities in a way that avoids being in Cordoba on Monday (most major sites are closed). And I wanted to break the trip up in Cordoba because Granada to Seville was a bit too much sitting time for me. But otherwise the order doesn't make a huge difference.

Checking on what is / is not open on Mondays is a good idea! And note that many things are closed for several hours in the middle of the day.