Jedi can still use their force powers, and you can do vastly more with it than what most games have included (one reason why I'd like to see Star Wars in Fate), and if Wardens get to keep their swords, then Obi-Wan gets to keep his lightsaber. Wardens can't sneak up on him, can't outmaneuver him, he can still deflect spells with the Force, and their swords are useless as offensive or defensive weapons against a lightsaber.
Obi couldn't take on more than a couple at a time, maybe only one, but one-on-one...Obi would own them. He's faster, smarter, precognitive and has a weapon they couldn't handle safely that can literally destroy their swords and they can't shield against it. Then he's got a broadly useful form of telekinesis that they can't do anything about unless he uses it offensively, which he won't do. Thaumaturgy won't help them, because if they get prep time, he gets time. He'd sense that it'd be a bad idea before doing anything that might allow them access to a connection with him, and he'd sense any kind of "landmine" spells before getting anywhere near them. Area spells can be dodged, and Jedi can do so earlier and more quickly than anyone else (unless under heavy crossfire like in ep 2). Ray-type spells can be deflected with the lightsaber (because there's no way they can deflect a blast from a heavy laser turret but not a dinky Warden. No way is a Warden's beam is more powerful than a plasma-based version of a howitzer, not if directly deflecting a bullet from a handgun takes so much juice...they just wouldn't have the power, not even McCoy with the Blackstaff).
All that said, a single Warden isn't enough to take out Obi, though two might do it. Any Senior Council member should be able to do it, just because they'd be less direct with their attacks and defenses. Old Wardens (even the improvisational ones) are too linear to do anything worthwhile, and young Wardens just don't carry the experience or metaphysical oomph. Wardens are sledgehammers, not scalpels...not even Luccio, for all her apparent finesse in combat. Wardens are the Judge Dredd of the metaphysical world...and that's a severe weakness. They're like Sardukar, Jedi are closer to Fremen. Heck, Luccio's only saving grace was that she got mind-controlled and ended up having an affair with Dresden...did a world of good for her perspective. Before, she'd have been a threat to a Jedi Master, but still would've lost with her uncompromising attitude. Jedi train specifically to fight Sith who think exactly that way.
Ultimately, Yoda could take them all, period...like a little green buddhist psychic ninja with a laser sword.
I say all this but I freely admit that while I like the ships, the sabers, some characters, and some Jedi philosophy, I don't really care at all for the overall story of Star Wars. Lucas did much better with Indiana Jones, and I think that was mostly thanks to Spielberg. George Lucas is what M. Night Shyamalan could've become if only he hadn't made his movies so dull.
Your forgetting their ability to augment their physical abilities to levels just shy of the "Inhuman" series of powers, if not equal to them.
On a final note...the spellchecker supports Jedi...but not Sith, Sardukar, or Fremen? WTF?