Thank you for listening!
I think the reason the woodwinds were more present is simple because I had to restrict myself from using the other themed instruments in many of the songs. I also didn't want every song to just solely focus on the theme instrument as I felt that would get boring if every song was just one of them. Having woodwinds be the constant instrument I felt made the OST connect together whilst allowing the themed instruments to be where they were needed.
Specifically for the choir I used, it had a very limited range. I wanted to use it more, but it couldn't hit notes I needed it to hit so it was kind of forced to play a supporting role. That made the battle track a little tricky since it was the themed instrument which is why the woodwinds took a much greater focus on that one and choir was support.