Me hit you, you hit me, who still stand win

It was called the stone age for a reason...

Groblok: Groblok has fist. You, mocking puny human from the future, has a face. Groblok clever. Groblok can fix problems with tools that are present. Groblok is going to fix your face, mocking human.

This is where the lizard and Spock comes in

Just you wait until we add a fourth thing

Unga throws beak.

Bunga throws water.

Beak beat water.

Unga win.

A single finger for a wooden club, beaten by rock that breaks it & a cupped hand for water, that rock sinks in (looses) and wooden club flosts on (wins). Sorted.