On my 8 buggy and truggy i run 2 aluminum and 2 composite. Its just what i'm used to. I don't know if one wears better than the other but together they seem to make a good combo. Of course you can only do this if you run a clutch with 4 shoes. Its just a personal preference, try out all 3 combos and see which you like best and what wears the best on your track. You might find that in your setup 4 aluminum works best, or you may find otherwise.