Multiple Sharepoint 2013 Content Types for Projects

I plan on storing project documents such as Scope docs, Business Requirement docs, Technical Design Docs, Status Update docs, etc. Would I create a Project Parent Content Type, and then have child content types for the docs I mention above.

Alternative would I just have 1 Content Type called projects and create a site column called Project Document Type.  Note I would not anticpate I would ever create a new document for these content type(s), I would only be uploading docs to these content types.

I have read that you should not create too many content types which I understand, but I also want to balance out the searchability factor with the usability factor.