no one is better than a-rod, but take a look around the rest of the league. there aren't that many good 3b around and if a-rod leaves you'll join the rest of us 95% of the league who doens't have a great player at the hot corner. wilson betimit could start for quite a few teams at 3b, obviously you'd want someone better next season, but that goes for most positions on most teams.
as far as your comparisons go, cairo was a starter at the beginning of his careerwith the cards and betimit has always been a utility man--cairo wasn't a utility man till he came to the yanks. a better way to look at it would be by number of at bats, not number of seasons. no one's saying that betimit is a great player or anywhere near arod, but he definitely has more pop than cairo