23^3 power cubes?
That is 12\'167m^3. If only 1/3 is filled with reactors, it will be 4k+ reactors, but I think you need about 5-6k reactors.
I prefer 127x7x7 which only requires 3k+, easier to setup and has enough space for 1 million storage - or some AMCs and shields if you want a Turret/Reactor with slightly more width/height.
It will matter as soon as docked ships add mass to the dock ship.
BTW: You can use ship docking units and let them just fire at selected targets in front of you, if you think they are ugly as turrets. Or rotate the weapon cpu and let them fire backwards at ppls following you.