I do not write country but write just about everything else. I can work it both ways. Most recently I have been presented with lyrics so I have to work lyrics first. LOL
I have written with melody first and with lyrics first.....it all depends on the mood and the project. Sometimes but not very often I do both at the same time. A melody and words come to mind at the same time.
At the end of the day it does not matter..it is what works for the individual and the end product that counts. Nothing should be carved in stone and writers should be prepared to tweak both lyrics and melody to get a balance. I hate it when co writers refuse to change their lyrics to allow meter or tunesmiths refuse to alter melody.