Even if a HK is as good as ten Clones, that doesn't mean a lot. An assassin won't win against a solider in a straigth fight. If the HK droids is attacking the Jedi head-on, which can be expected in this sort of situation, the Jedi will win.
Why do I keep hearing that Jedi will be sleeping, mediation, taking a crap, ect when Ragnos attacks? He is effin good. When someone that powerful comes knocking at your door, your going to get you ass of that toilet seat and grap the nearest weapon. All ten thousand Jedi will be ready to fight him.
Illustrious, if you compared Ragnos to an average Jedi individually, how many times more powerful do you think he would be?