personally I edit /storage/.kodi/usersdata/sources.xml as the format it simple and typing smb://user:pass@SERVER/SHARE is easier on a keyboad via SSH than using a remote in the GUI.
Oh man, that is so much easier I also just discovered the 'System Tools' addon which gave me vim \o/
I have one video source which I use the most, but it's listed last in 'Videos > Media sources'. I edited the sources.xml and put the source I use most often at the top of the list, but that didn't seem to affect the sorting.
Is there a way to (manually) change the sorting? If so, how?