Marion, I really believe that we should have duplicate fingerings for virtually EVERY chord. It simply allows you to go in more directions with the sound. I wouldn't play the D chord using the last three fingers, BUT if I'm in a dropped D tuning I usually finger D with a three finger index barre, and the middle finger on the second string, third fret. I can now use my ring finger to play the F# note on the sixth string if I'm using a "walking bass".

If I play the "G" with a D instead of a B on the second string then I switch to a "first three fingers" G. Never thought of it as an "Indigo Girls" chord, but ya learn something every day.

Rather than a "right or wrong" fingering, I'd rather think of "primary" fingerings, and I often describe chords as being "tight or loose". For example, an F without the root bass note seems very "loose" to me, which is why I try to show all my students how to use their thumb on the sixth string. Naturally a full barre works fine too, but a "thumb chord can be faster and works great in "ragtime or blues" music.

Rick