Welcome to the forum!

The first thing to try:

MIDI/Audio menu > Reassign Playback Sounds

Hey Peter. I tried this, but i ended up getting the blue circle of death. It crashed the program (I did the reassign playback after changing the instruments in score manager from "blank staff" to the correct instrument).

I then re-opened finale and reimported the xml. This time, I did the reassign first. This allowed playback, but wrong sounds. So, I opened scoremanager and changed the "blank staff" to the correct instrument in the marching band list. This fixed the sound problems for the winds, but percussion is still wrong.

… This fixed the sound problems for the winds, but percussion is still wrong …

If I understand you correctly, the problem is now that the percussion does play back, with percussion instruments, but with the wrong percussion instruments - right?

I would examine the Percussion Layout.

If the right sounds are available in the Percussion MIDI Map, then you can solve the issue by creating a new Percussion Layout that uses the right sounds, and notates them at the needed staff positions.

https://drive.google.com/drive/folders/1HHBN9sXo62p9PewpeOPaHKQBD4Z2BcbR?usp=sharing 

Take a look at the 10 second clip in this drive folder. You'll see that the imported file has percussion notes highlighted for some reason. You'll also hear the sounds

It sounds like the Cymbal Line plays back with a Piano sound.

1) Are you using the option {Play Finale Through MIDI}? (look in the MIDI/Audio menu)

Make sure that all Percussion staves are on Channel 10 (= the Percussion Channel).

My guess is that the Cymbal Line is not on Channel 10.

2) What is going on in the Bass Drums staff? How is it supposed to sound?

3) I do not hear anything from the Drum Set staff. Do you?