This is totally reasonable. MongoDB, more than any other "NoSQL" database, directly competes with MySQL/Postgres as a general-purpose application database. I do

This is totally reasonable. MongoDB, more than any other "NoSQL" database, directly competes with MySQL/Postgres as a general-purpose application database. I don't see a need to have more than one for most applications - at least as long as there is only one development/support team for that application.