Moments after the leader is done speaking, he's already dead. His minions, startled, likewise prove easy prey...easy enough to defeat even though there are three of them to your one. Before long, all four of the closer thugs are down. Time for the two further ones.
Chase after the two further thugs and try to get rid of them before they do the same to Lou. For that matter, don't rely on chasing them at all. Yell to Lou to warn him right away.