This is the primary tactic of the Yamani Empire in Open Blue. The Zerg Rush, combined with bushido.
This ends up being the only real recourse of the forces of hell in The Salvation War: Armageddon. Due to the fact they're at bronze age levels of technology and are up against modern armies, its not like they have much of a choice...
From the Global Guardians PBEM Universe: Los Hermanos is a duplicator who can create thousands of clones of himself. Other than that, he's basically just an athletic, somewhat skilled martial artist. Guess what one of his primary tactics is when fighting a villain who is obviously much more powerful than he is?