Wow - now that's a blockbuster! Is it fair? Yes, but I still think one side wins by a nose.
First off, I like Aurilia for this year. No, he won't reproduce his 2001 numbers, but expect something like .300 avg, 100 runs, 25-35 hr, 90 rbi. Not too shabby for a shortstop... If he tapered off at the end of last year, consider that he hit the bulk of his homers after the break.
Nonetheless, I'd still rather have A-Rod and Hudson. A-Rod and the Big Unit are essentially a wash, and I value Hudson a bit higher than Aurilia. (According to our top 100, Johnson and Rodriguez are numbers 1 and two, although you might call them 1a and 1b; Hudson is at 19, and Aurilia is #61, or the sixth-highest ss).
But while A-Rod/Hudson might have slightly higher value, it's close enough that your team composition might tilt the balance toward the other side, for instance if you're desperate for strikeouts. All else being even, however, go with those two.