I don't know.
As a composer myself, I feel that BG 3's music is actually pretty good in terms of variations you can create on a theme. We have the nice slow version with "Down by the River". Then we have the Epic version. Don't get me started on how the music cues a triumphant version when you kill an enemy.
Although I do hope we have MORE tracks for fights.
BG soundtrack felt more on the nose and that can REALLY work. I love opening up that title screen and thinking I'm gonna go on an adventure. BG 3 is more subtle. It's telling me "You don't know what's coming."
One says "Let's go!" While the other says "Follow me...see the world that awaits"