Sure you can, but first you'll need to edit the orchestral dls and the included sgt's with DirectMusic Producer.
I can explain:
- First, insert the orchestral dls + every sgt's except "024s-march1.sgt" since this one isn't orchestral (makes 5 sgts). (right-click "Project1", insert)
- Create a new DLS Collection. (right-click "Project1", new..., choose "DLS Collection")
- Copy and paste into that new DLS, from the orchestral DLS, the following instruments: "Don't Be Afraid: 0,1,0", "Man With the Machine Gun: 0,1,2", "Helicopter: 0,0,125". (Helicopter contains "Balamb Garden" and "Blue Fields" orchestral tracks)
- From the new DLS, change the bank and preset assignment to something else since they're conflicting with instruments from my DLS. Let say 100,100,0 for "Don't Be Afraid", 100,100,1 for "Man With the Machine Gun" and 100,100,2 for "Helicopter" to make sure they will never interfere. Double-click on each and change those three numbers situated just below the piano roll that appears on the right (named MSB, LSB, Patch).
- Since the instrument's position has changed, you'll need to reassign the instruments from the SGTs. Double-click on the sgt to reveal the title. Double-click on that title. To the right on the last row, double-click "Band1" ("Band2 for "012s-kani.sgt"). Double-click on each instrument, choosing the right one.
- You can also take the opportunity to fix the volume instability if you know DM Producer well enough.
- Save every SGTs and the new clean and compatible DLS somewhere on your hard drive (right-click, save as).
- Delete everything from DirectMusic Producer, since those are only copies of what you inserted at first and close it. But make sure you saved them somewhere else ("save as") not over ("save"). They will enter the recycle bin.
- Browse to the directory you saved the files and rename the ".sgp" files to ".sgt" and ".dlp" to ".dls".
- AT THAT POINT YOU CAN MAKE A BACKUP OF THOSE FILES READY TO BE MERGED WITH MY DLS (except "024s-march1.sgt" which isn't needed).
- To merge both DLS's, open my DLS with Awave. In the "File" menu, click "Merge files...", browse to the new compatible orchestral DLS and save the new merged DLS as "FF8.DLS" directly to the "dmusic" folder. Don't forget to save it as a DLS Level 1.
- Also copy the modified SGTs (or only those you want orchestrated) into the "dmusic" folder.
Then everything should work perfectly as I just tried it.
I hope I explained it well... let me know if something's wrong or doesn't work.