Clearly, the developers recieved the music from Dråm uncompressed / high fidelity and they compressed the hell out of it to keep file size down... on second thought those .al files are still as big an mp3, just doesn't sound as good as one.
Here's one of the Dominions III compositions from the Dråm website:
http://www.draam.com/mp3/Draam_Hornlaat.mp3 (sounds much better than in game)