See I don't have a problem with multiple Guards doing so, because there were a great many of them that were laying seige to Nyriss' stronghold, the defenders unprepared and not organized.
Problem I have however, is 1 Guard being able to kill a full Sith Lord, because this would be ignoring that Force Advantage the Sith Lord has over them, they aren't Jedi....they won't play nice and just stick with strict bladework. It doesn't really help that said Guards just ran head long into blaster fire and just died, now how stupid is that?
As the smoke cleared, dozens of red-uniformed soldiers poured through the breach, armed with blaster pistols and electrostaffs.Nyriss’s people opened fire, mowing down the first wave. Those in the ranks behind never even slowed. Driven forward by their furious devotion to the Emperor, they charged the enemy line with a reckless disregard for their own safety.
This would be something I'd expect from like Sith Troopers, not Guardsmen.
Heck even against Scourge, Yarri knew she couldn't win and had to have a 2nd Guard come aid her and he was only struck because he was distracted with visions.
Captain Yarri’s skill with her electrostaff was impressive, but ultimately she was no match for a Sith Lord. Knowing this, she had wisely adopted a defensive style to hold off the first few flurries of Scourge’s attack, her focus on stalling him long enough for one of her companions to join the fray before switching to a more aggressive form.Now Scourge was forced to defend himself on two fronts as he backed into the throne room.
The fact that Revan hadn’t come to their aid told Scourge that the Jedi had gone to confront the Emperor, conjuring up images from Scourge’s vision of him lying broken and beaten on the floor at the Emperor’s feet.
Yarri’s staff slipped through his defenses and clipped him on his right shoulder. Scourge’s armor absorbed the worst of the blow, though he felt a painful jolt from the electrostaff’s charge that made his hand and arm tingle.
Even as Scourge cursed himself for allowing thoughts of his vision to distract him