What is the offensive distribution between the stardrive and saucer section on a Galaxy class star ship?

I am wondering about the combat effectiveness of the saucer section of a Galaxy class starship is compared to the stardrive section.

I know that the saucer section can sustain a warp field but not generate one. I don't know if it can change direction. I also do not know how crucial warp drive is in combat, I think they combat generally happens at impulse.

So, what I would like to know is:

1. what the distribution of phasers and torpedo launchers is and if know what their angle of fire is(do either of the sections have blind spots they cannot fire in).


2. Do both sections have comparable shielding?


3. Is the stardrive section more or less manoeuvrable on its own?

Additionally, I see basically three reasonable situations where you would separate the ship: 1) To have multiple vectors of attack, 2) To leave non-essential personal behind and 3) You need to do a crash landing.

I have seen 2 and 3, but I am not sure I have seen a combat situation using both sections on a Galaxy class before. Is multivectored attack viable in a Galaxy class or is that the just domain of the Prometheus class?

Answer

Phasers

As can be seen in the below image from 'The Best of Both Worlds Pt I', we see the Enterprise-D firing phasers from both the saucer and stardrive section:

(Source)

Torpedos

The above image demonstrates that torpedoes can be fired from the stardrive section (it's clearly coming from below the saucer section). This is showing a front torpedo-launcher. This image shows that the stardrive section also has an aft torpedo launcher.

Looking at the below schematic, it seems that the saucer section may also be capable of launching torpedoes:

However, this is an aft-torpedo launcher, so in terms of weak spots, the saucer-section wouldn't be able to fire torpedoes from the front. However, it does have phasers there!

Memory Alpha tells us that:

Shield energies could be emitted from a localized antenna or "dish", such as a ship's navigational deflector, or from a network of "grid" emitters laid out on the object's surface, such as a starship's hull.

As the saucer section obviously lacks the main navigational deflector, I would postulate that it uses the latter i.e. a network of grid emitters. It also doesn't make much sense to use saucer separation next to a Borg Cube if the saucer lacks shielding! So, I would say they both have shielding.

In terms of power, as the saucer section lacks the matter/antimatter reactor, it wouldn't be capable of producing the same amount of energy, therefore I would expect the saucer section's shielding to not be as strong as the stardrive section's shields.

I have found no information to suggest that there is any particular advantage in terms of the stardrive section's maneuverability following saucer-separation. It stands to reason that it would be somewhat more maneuverable, considering that it doesn't have the saucer section to interfere with operations.

The Saucer section has the impulse engines ('The Best of Both Worlds Pt I'), so that would be a very maneuverable sub-light craft in its own right.

Yes, multi-vectored attack is both possible and seen. In 'The Best of Both Worlds Part 2', the Enterprise-D engages the Borg cube in such an attack with the saucer section firing antimatter streams and the stardrive section engaging it simultaneously.