Bagpipe score:

https://www.bagpipelesson.com/bloody-fields-of-flanders-bagpipe-sheet-music.html

Differences: the three even beats at the end of the first part (that throws you if you knew the song first) and it's twice as long as the song, with variant repeats in the second part.

So you could tell whether a band was playing the original march or the song if they were doing it as a wordless anthem. Pipers do sometimes get a bit aerated about song tunes and their pipe versions getting mixed up. Iain Grant got annoyed with me more than once for playing the song version of MacPherson's Farewell when he wanted to do the pipe band one.