I dunno, I find it pretty dubious. Liking your co-workers obviously has an effect on how much you like going in to work, but I've always found that a group's output is completely dependent on the team's level of ability and quality of management.
And I don't think you can target players that will enhance chemistry. Throw Josh Donaldson, or Omar Vizquel, into one room and 22 guys might love them. Throw them into another and they might rub the majority of the room the wrong way. That's not to say that the team should force it's employees to deal with John Rocker or Milton Bradley, but that outside of a few guys who are batshit insane, it's probably not possible to know beforehand how well they'll get along with the people already in the room.