1500 M is big enough to hit with the main weapon. Mon Calamari Cruisers are only 1200 M in length and the DS 2 blows up two of those and a medical frigate which is even smaller, in the battle of Endor
Also while the design team on First Contact made that sphere 1500 M in diameter, they are listed in the tech manuals as being 3000 M in size.
1500 M is big enough to hit with the main weapon. Mon Calamari Cruisers are only 1200 M in length and the DS 2 blows up two of those and a medical frigate which is even smaller, in the battle of Endor
Also while the design team on First Contact made that sphere 1500 M in diameter, they are listed in the tech manuals as being 3000 M in size.