Giving up Christian Yelich may seem to be too high a price for a youngster like Christian Arroyo, and on the surface, may seem to be a lopsided trade in favor of the Brewers. In response to those types of observations I offer this:
Arroyo is 21 years old and has been productive at every level and in every situation he's been a part of. The Giants have groomed him for success and I believe he's going to be a fixture in the Giants infield for many years. Although he will probably lose his MI eligibility after this season, he is going to be a productive CI. With Panik and Crawford, the FGM (and real life) Giants have a solid infield that is young, productive and will get better.
OFs like Yelich, as productive as he is, are easier to replace than CIs, and the Giants OF is a position of strength, and affords them the opportunity to roll the dice in a trade such as this one. Arroyo was snatched in the FYPD by the original GM of the Brewers (Brewers GM) before the Giants could draft him, and is a player the Giants have coveted for a long time. Just like their pursuit of Joe Panik, the Giants have been relentless in their attempts to add him to their roster. Finally, after years of trying, Christian Arroyo joins the team of his origin.
Some may categorize this as a misguided homer decision, and in a sense it is, but it is based on a belief that Christian Arroyo is going to be the real deal for many years to come.