Its not a trade off. Green was only good offensively in April and May. From June to September, he batted .233, .143 and .189 (.167 in 2nd half). September he just got 6 ABs
They made the trade for A-Gon because not only had Green's offense slipped, but his defense was also. He showed why to not give bench players too much ABs
Scutaro from June to September batted .229, .355, .274, .211 (.272 in 2nd half). He was shut down in September because of his ankle