How can I increase the number of unit attack sounds?

[tlstkwjr]

For example, Rifleman repeats each time he attacks two sounds, riflemanattack1 and riflemanattack2.
I want to grow this sound pool. play more sounds randomly rather than play two.
is this possible? If possible, how can I do?

 

[Warseeker]

Sadly Warcraft 3 doesn't let you add more sounds to units. You can only overwrite the existing ones. However, the best you can do is to create you own sound set for that unit using triggers.