Waiting to see young YP is my usual suggestion for the first stocking of SMB. In a relatively weed free pond the predation by SMB on YP often eventually out paces the YP production. Good management is important for producing a high quality YP fishery with SMB that annually recruit new smallies. Adequate forage is often the weak link in a YP-SMB pond which is why I like to use pellet trained stockers with YP&SMB combination.
aka Pond Doctor & Dr. Perca Read Pond Boss Magazine - America's Journal of Pond Management