I looked at the Sox active roster which right now lists four outfielders--Betts, JBJ, Benintendi, and Holt. Total salary for all four is a tad over $2M--by far the most cost effective MLB outfield on a single team in a long time.
Dombrowski gets credit for bringing Benintendi up, but I am less sure that he is the ace GM some say he is. The Tigers fired him and are better since he left.
He didn't need to do much to fix the lineup which already was going to be very good. The best improvements were moving HanRam to 1B, which was inevitable before Dombrowski got here, and the injury to Sandoval. Sandy Leon is a nice surprise at C, but the Sox got him last March, before Dombrowski. The Sox have the best overall lineup in MLB and very little credit goes to Dombrowski.
His report card should be based on fixing the pitching, and so far that is a mixed bag. Price right now is paid the 3d or 4th highest salary in the history of MLB and he sure ain't living up to it. Pomeranz just might work out, but at the cost of a highly regarded minor leaguer (I personally thought the deal made sense, which suggests it probably did not). Our two best starters are Wright and Porcello, for which Dombrowski gets no credit. ERod, estabished here before Dombrowski arrived, is finally looking like last year and could become our 3d best starter ahead of Price. Dombrowski made the decision to keep Buchholz at $12M/year, and that has not paid off. Kimbrel, despite some issues, is a plus. Abad is a firm minus. Ziegler is a mixed bag.
Feel free to disagree.