Your developers should strive to appear in the project's public forums as individual participants, rather than as a monolithic corporate presence. This is not because there is some negative connotation inherent in monolithic corporate presences (well, perhaps there is, but that's not what this book is about). Rather, it's because individuals are the only sort of entity open source projects are structurally equipped to deal with. An individual contributor can have discussions, submit patches, acquire credibility, vote, and so forth. A company cannot.
Furthermore, by behaving in a decentralized manner, you avoid stimulating centralization of opposition. Let your developers disagree with each other on the mailing lists. Encourage them to review each other's code as often, and as publicly, as they would anyone else's. Discourage them from always voting as a bloc, because if they do, others may start to feel that, just on general principles, there should be an organized effort to keep them in check.
There's a difference between actually being decentralized and simply striving to appear that way. Under certain circumstances, having your developers behave in concert can be quite useful, and they should be prepared to coordinate behind the scenes when necessary. For example, when making a proposal, having several people chime in with agreement early on can help it along, by giving the impression of a growing consensus. Others will feel that the proposal has momentum, and that if they were to object, they'd be stopping that momentum. Thus, people will object only if they have a good reason to do so. There's nothing wrong with orchestrating agreement like this, as long as objections are still taken seriously. The public manifestations of a private agreement are no less sincere for having been coordinated beforehand, and are not harmful as long as they are not used to prejudicially snuff out opposing arguments. Their purpose is merely to inhibit the sort of people who like to object just to stay in shape; see the section called “The Smaller the Topic, the Longer the Debate” in Chapter 6, Communications for more about them.