Scotland the brave is quite a nice tune but not the type you want for a national anthem.
Why not? What sort of tunes do you find appropriate?
A few reasons:
1. Scotland the Brave is fast. Really really fast. It is difficult to fit any words to it and even if you succeed it will be difficult for people to sing them, and national anthems should be fairly easy for even the unmusical to sing.
We Mormons have managed to get lyrics for that tune just fine thank you very much. No problems whatsoever. It can be done just fine.
Actually I've heard more than my fair share of creative lyrics put into that have been manageable
So yeah, it's doable.