Forget the teams - who knows who wins or loses until after the year, or longer. Did the Twins win the Kurt Suzuki trade? The Aaron Hicks Trade? The John Ryan Murphy trade? The Wilson Ramos trade? The first year is not enough to judge (although potentially the Betts trade is for a one year player). Injuries, slumps, high expectations all play into the team win or loss, but the players factors are not the same as the team.
As I look at benefits to individual players I see a different pattern of potential winners and losers.
Mookie Betts - he wins. He would have won if the trade had not happened because he is going to get a Trout like contract and now he has a west coast audition to go with his East Coast play. Yet, the teams have not figured out that one great player does not elevate the team - this is not the NBA - and Mike Trout has never been in a WS. Trout, Harper, Betts - all far over paid, so yes, he wins, but the Dodgers will win the west (they won without him last year and the year before and would have won without him this year). Will the Dodgers win the World Series - they will if their pitchers lead them or if Mookie Betts has a crazy year like Bobby Richardson of the Yankees, or Dusty Rhodes of the Giants, or Scott Podsednik of the White Sox, or Jim Leyritz of the Yankees, or Kurt Bevacqua of the Padres, or Brian Doyle of the Yankees? Those are not memorable names or players yet they were the biggest reason for their teams success. Notice it is not Mantle or other big names on this list and history is filled with even more obscure names. So will Mookie win them a world series? No, but he might be on the team that does win and if he does that big contract is waiting.
Graterol - he wins - the Dodgers Bullpen is aging and Jansen is not as good as he once was so Graterol jumps into a great position if he stays in the pen. The Dodgers have lots of successful arms and seem to know how to use them. If he moves to SP he will succeed there too with good fielding and good hitting all around him. Much better than Red Sox - no green monster, a deteriorating team, and a questionable staff.
Kenta Maeda wins - with the Dodgers he is in the bullpen after they got Price and they have so many ready arms he is expendable. With the Twins he is expected to win the World Series! Yes he is now our #3 pitcher until Pineda returns and then he is number four and after free agency calls Odorizzi he will rise again next year.
Luke Raley loses - if he thinks he was blocked by the Twins prospects and starters he is now back in the Dodger prospect factory and will lose more until he is traded again.
Connor Wong - wins - they say that the Red Sox need catchers - he will find a place on the catcher bench.
Jair Carmargo - loses - the Twins have Garver, Rortvedt, Jeffers - young and versatile. But hey every team needs a catcher in the minors. His only hope is another trade.
Jeter Downs - not sure - probably a win. He has a good name for a shortstop. Bogaerts will eventually move from SS and probably not that far in the future and Jonathan Arauz does not have dazzling Milb stats so Downs moves into the number two position. With the Dodgers his window was not open.
Alex Verdugo - wins - he has shown that he has talent. Expectations in Boston are not that he will replace Betts, but he will start and he could like the monster. And now he does not have Luke Raley looking over his shoulder! I think he will thrive.
David Price - wins - yes he is a salary dump, but he now moves into the Dodger rotation replacing Ryu and Maeda. He is with Walker and Kershaw - not bad and his expectations are less. There are no DHs, there is good fielding. What is lacking is a great pen, but hey, they got Graterol out there now. I think he might become a star again if health allows.