I think it's a valid comparison, in terms of major changes and time needed to regenerate chemistry.
Chemistry is something that GMs happen on when they have success, and then too often get rid of it.
For example, Danny Ainge happened on great chemistry with his starting five and won a championship.
He then let his key bench player, Posey, go to free agency. He now has traded his defensive center, Perkins, one of his original starters. The Celtics haven't repeated their championship. And if they fail this year, it will likely be due to the center position more than anything else.
Epstein made two good signings last year in Beltre and VMart. The Sox did surprisingly well last year until injuries to Youkilis and Pedroia. But Theo loves AdGon and made a good trade for him. He let Vmart and Beltre go--two main RHd power hitters against lefties. Replaced by Crawford and AdGon, two left handed hitters. Upsetting the lineup balance. The result is teams are throwing left handed pitchers at them any time they can. This is bound to affect their hitting, because the platoon RHd hitters they have aren't as good as VMart and Beltre. And Crawford and AdGon aren't going to hit LHders as well.
Epstein has messed with the chemistry--the balance of hitters in the lineup. And the Sox are taking some time to adjust.