They had a 10% bigger brain case than modern humans. Do not assume they were necessarily less smart.
If modern humans were faster and had more endurance, then Cro-Mags could hit a Neanderthal camp in a surprise raid, kill a few, and then run away. Then circle back and hit any pursuit after the Neanderthals were exhausted from the chase. Repeat until you run out of Neanderthals.
I've read in several places that early humans were built to be corsairial hunters, chasing prey until the prey dropped from exhaustion. This would allow us to keep up with a herd of prey, taking down the weaker members as they dropped or straggled.
See number 20 above...