In reality, although there is only way for those proposals 'To be created at the discretion of each individual salesperson', but their Sales executive must always worry that "I suspect if they present sloppy proposals..." But possibly, there might be a guy who is making 'a once in a lifetime proposal' at this moment. (It's the communication that counts!)
In anyhow, we would like to visualize 'the progress of creating proposal' for re-usability of it, and want to develop an environment conducive to give and to receive advices from colleagues. Here, we try to implement a business rule of "Get reviewed by at least one person before submit!" with Workflow.
[Proposal and Review flow(Taskfeed) ]