Here are their numbers in the majors, followed by their numbers at Triple-A:
Sogard is 25, Donaldson is 26, and Rosales is 28. The major league numbers are in such small samples that we can throw them out for Sogard and Donaldson. Given their ages and their comparative numbers, it's clear to me at least that Sogard should get first crack at this job. Donaldson's bat played better as a catcher, and Rosales is not likely to catch lightning in a bottle when he should be entering the prime of his career.
Here's the issue - it's likely that only two of the three make the team. Sogard and Rosales can play almost anywhere, whereas Donaldson is much more limited. Do you use Sogard at third and have Rosales move around the diamond? Would you give Sogard the job, have Donaldson as the "utility" infielder and Sogard simply takes the place of whoever gets the day off?
To be fair, the effect of this decision is a win, maybe two. And all three of these guys are going to play this year, probably quite a bit. We're still talking about the Oakland Athletics, so whoever gets the job will be hurt by mid-April. But, evaluating them as baseball players not only for 2012 but beyond, it's clear that "Sogard 5" should appear on the lineup card on Opening Day.