They don't use general midi standard instruments. You need the extracted soundfont because the instrument numbers are unique to each game. In order to "improv

They don't use general midi standard instruments. You need the extracted soundfont because the instrument numbers are unique to each game. In order to "improve" the soundfont, you need to edit that soundfont to have higher quality instruments, you can't just switch out the whole soundfont for a different one.