But why though?? The army of light wasn't fighting the void and the old gods because they were being led to wipe out essentially the forces of disorder
The naaru are the only real light reps we have and they hate the void and everything they deem unworthy
The void reps are 100% take over everything because that's their nature but to say light vs void is a huge cosmic situation is kinda stretching based on what we know.
The light is essentially a full blown hivemind which is the opposite of the void which is everything is free will with one goal.
Sargeras was supposedly the light's champion and we know what happened there and with Illidan