While the information contained in the provided sizing guide (http://www.symantec.com/docs/TECH103675) is helpful.  It lacks clarity when attempting to design an implementation with a physically separate SEPM and database. 

Improve the sizing documentation to explicitly mention details like backups are kept on the SEPM rather than the DB.

Ideally two sizing guides, one specifically for SEPM application server, and one specifically for the database server.