Depends on your needs. For simplicity and making most of auto-detection keep everything in default subclient, for better control split it appart either manually or by utilizing the Subclient Type Setting (General Tab of Subclient Porperties).
Personally I left most of it in default and used AdditionalSettings bSkipTLForSimpleRecoveryModelDB, bSkipTLForReadOnlyDB & bSkipDiffReadOnlyDB to reduce the amount of unneeded conversions to Full-Backups. Only if some DB needs special Retention or more frequent schedule I moved it to separate Subclient.
Hope that helps,