I've tried using the file path of the original Firaxis sounds for my infantry unit but for some reason I can't get them to work in game. So I am wondering if it would be kosher if I included original Firaxis sounds in my unit folder for download, provided that I have a Readme.txt file which explains that the sounds are original Firaxis ones.

Thanks.

You've presumably purchased C3, and scads of mods & scenarios are to be found here with Firaxis graphics, so I wouldn't worry, as non-commercial use of such is generally perfectly legitimate.

BTW there is a rumored problem in using relative pathways with .amb files; that might be your problem.

Best,

Oz