The Red Sox won the World Series last year because they were the best team in baseball, it has nothing to do with "morale".
Team's can have worse "chemistry", than men with thier mother-in-laws, if they are the best team in baseball, they will win.
For example the the A's of the 1970's. Those guys got along worse than teenage girls, they beat the s*** out of each other every day in thier clubhouse. Players actually got injuries, by getting in fights with each other. They didn't take it with them out on the field and won the World Series in '72, '73, and '74. As terribly as those guys got along, they still won.
Those players didn't "Play for each other". Reggie Jackson left as soon as he could, they had the best team and they won.
Chemistry is over rated. Especially here in Boston.