Well, I always felt two takes on the Star Trek universe is better than one..
Why do the ds9 pylons curve inwards? Even for multiple small ship docking the manouvering woiuld be more hazardous than if they curved outwards. It's just aesthetics.
Or then it's the same thing as with harbors today. It's easier for ships to moor on the "outsides" of piers and jetties, from the maneuvering an congestion points of view, but it's safer and more practical for them to moor on the insides, away from the waves and winds and perhaps even separated from the tides by a series of locks and gates.
DS9 supposedly does feature a spherical forcefield protecting it from outside attacks. Ships docking at the tips of inward-turned pylons would enjoy the protection of that field, while ships docking on the outside would not.
Which reminds me of another aspect of the Defiant
docking issue. In "Way of the Warrior", the damaged and useless ship docked at her regular outer ring port at the end of a chase. The Klingon fleet then attacked. From that point on, the Defiant
was nowhere to be seen.
Did the ship remain at that outer port (which was admittedly initially facing away from the Klingon fleet), or did it get moved to somewhere supposedly safer? During the battle, we saw dorsal shots of the station, revealing many of the docking pylon tips, but IIRC none revealing all of them; we also never got a view that would have revealed all the docking pylon / outer ring junctions and established that the ship had been moved. But would an outer ring position be secure during the battle?
In "A Call to Arms", some of the smaller Dominion vessels actually flew between the pylons and crashed to the inner structures. Enemy fire also penetrated that far. But in "Way of the Warrior", no ships intruded into the area supposedly protected by the spherical forcefield, and only the heaviest enemy fire from Gowron's flagship hit the inner structures (an action associated with the collapsing of the shields). In contrast, the red beams from the waves of old battle cruiser prompted fireball explosions at the outer rim. Would not the poor Defiant
have been toast pretty quickly?