It doesnt matter how good he think he is, he is someone who is trained by the force, and should be pretty strong, atleast the 3 most powerful force user in galaxy right now, it doesnt make sense for him to go down to people who have never use a saber before.
Being strong in the force doesn't mean shit. Even when the Jedi were at their height, all it took to wipe them out were a couple of clone troopers with blasters. Granted, they were taken off guard, but it should prove how even the strongest force users can die from a simple blaster to the back.
Remember, Anakin was considered the most powerful Jedi in the galaxy, and by the time he became Darth Vade, most of his body was replaced with machinery. That cut off a large amount of his potential, effectively weakening his access to the force. And yet Mr. Roboto still managed to hunt down and wipe out the remaining Jedi.