Really guys? Really? 1-2 with a HR will always give you better expectations than 2-2 with 2 doubles. Just assuming a team that gets on base at a .300 clip, the runs expectations will still be lower with a 2 double performance than a single HR performance. Sure, there are times when a player might have 2 bases-clearing doubles while another player has a solo HR, but expectation is a study of LONG TERM RESULTS. In the long term, 1 for 2 with a HR will give you a higher run scored expectation than 2 doubles.
Just a logic test: for a double to score a run or more, it requires at least one player to reach base. It also requires at least one player in scoring position the majority of the time. Now you are looking at 10% territory (and that's a generous number). A small percentage of the time, a double will score a run. A TINY percentage of the time a double will score more than one run. The stars have to align to reach the maximum run potential (6 runs). For the HR, 100% of the time you score at least 1 run. Assuming 30% on base, 30% of the time it's 2+ runs. With that assumption, 9% of the time it's 3+ runs, 2.7% 4 runs. That would be an overall expectation of 1.44 runs (0.7x1,0.027x4,0.09x3,0.183x2).
With a double: 9% it's 1 run, 2.7% 2 runs, 2.7% 3 runs. 85.6% it doesn't score a run, but adds a base runner. That added runner is then factored into the next hitter. Assuming a .300 average, 30% of the time that runner will score. That comes out to: 0.525 expected runs (expectations of runs scoring from the double + expectation of the subject then scoring). Double that to get the expectations for a 2-2 double performance and you have 1.05 expected runs.
I know there's a lot of estimations in there, but I did use the same percentages for both player A and B and based the scoring position odds on percentage of the time an Ellsbury or Pedroia plate appearance results with them in scoring position. Also, I probably should have used the 0.340 OBP of the Sox right now, but the results will be more or less than same: HR has the higher expection.