I think it's been mentioned before, but the fact that Dooku was so strong may have been reason why Palpatine allowed Anakin to defeat him. Also, one reason that Anakin defeated Dooku was because Dooku was taken aback by the treachery of his master (not because Anakin's powers "doubled"). And as for the "size matters not", I agree with that totally. The size of a Jedi master does not determine his level connection to the Force. Palpatine just plained owned on Yoda, having been holding back his powers for years, waiting for the right moment to strike. I think that Yoda could take out, say, Qui Gon and Mace Windu in battle, and they're mad taller than him. But Palpatine was just waiting too long, and was not going to let some green shrivled munchkin ruin his plans for galatic domination.