Excuse me for asking, isn't the lightsaber hilt made of electrum? Electrum is an alloy of silver and gold, and a good conductor of electricity.
Were Obi-Wan and Mace's lightsaber not made of electrum? Because Obi-Wan stopped Dooku's lightning with no ill effects, and the only trouble that Mace had came from the sheer force of Sidious's lightning - and the power behind it.
And, honestly, Zephiel - is the substance of the hilt itself going to be the primary weapon of your argument?
In this case, if Dooku decided to play things out tactically, wouldn't he just send his blast of lightning to aim for Vader's lightsaber hilt, thus providing a conductor for the lightning to enter Vaders mechanical body and screw him over?
Honestly, dude, I don't see that happening. But even if that is the case, how would Count Dooku know that the lightsaber is made from electrum, without analyzing it, first? Is electrum easily spotted at a glance?
Ben might be a bit of a problem...but he's out of practice. Dooku could take out Vader and isolate Kenobi, if what I said works out.
I don't see Dooku taking out Obi-Wan and Vader. Like I said, Vader's supposedly 80% of Sidious by RotJ (I keep forgetting if that is his potential or sheer fighting abolity) - and I don't see Dooku being much more than 80% - if he is at all.
I doubt the lightning will stop Vader. If that is the case, Vader's sheer physical strength could bludgeon Dooku to death as it is, being consistently stronger than Anakin. Obi-Wan would rank higher than just your general "distraction", too.
I don't see Tyranus beating them.