This is all simple.
Best practice is to disable the save and save as and have buttons like you have outlined.
No need for code.
Go to tools and Data Connections and add a submit connection to SharePoint. Set it up for your draft locations and use a concat function to create your naming scheme. Then create another submit connection for the policy committe. Then just have a rule on the first button to use the draft submit and the other to use the second.
This is all standard functionality that you do not have to over complicate. Once you try it you will see.