I've discussed how companies often assign one writer to a client, only to have a different writer assigned to the client once the project has begun, one who is inexperienced and unqualified.
Companies also occasionally use the tactic of "the closer." If a potential client is reluctant, the company tries to close the deal by having one of their very few qualified writers handle the final details of the negotiation, with the unspoken assumption being that the closer will be the person to write the book. After the contract is signed, the closer mysteriously disappears and a new writer takes over the project.
And don't forget to download your free copy of my book How to Hire a Ghostwriter from this site.