The big problem there is the capacity imbalance. The battle section can get to places fast, but it has virtually no resources to deal with anything except battle - it could not have handled the Constantinople
crisis alone because all the big medical facilities were on the saucer. Conversely, the saucer alone apparently could not have sailed to the hurt transport fast enough and rescued her from whatever calamity had befallen her, while the big engines and tractor beams and whatnot of the battle section would have been wasted orbiting Gravesworld.
Worse still, "Best of Both Worlds" suggests that the battle section suffers a reduction of its combat abilities when separated; for some reason, power from the saucer's impulse engines is useful or even essential in combat...
Sure, there are situations where the great habitation, storage, medical aid and research capacity of the saucer is best left floating at a destination and there is no need for either big engines or powerful shields or weapons. But few episodes feature such situations, even though those could have been rather easily written in and the vast majority of TNG episodes could have been launched with a Captain's Log stating "Stardate Today, we have left the saucer section at Alpha Omega and are now conducting a mission of great importance at Beta Epsilon". What simpler way to set up the A/B plot structure so endemic for the show?