Condottiere
SOC-14 5K

Technically, they're breakaway hulls.
If it's six seconds per combat round; accuracy increased the more you delay the shot to the subsequent rounds.
But over six, ten or twenty minutes per action, that's a large time period to fire off each weapon system.
...for energy based weapon systems, it depends on capacitors, batteries and direct power diversion from the plant.
Actual rate of fire can also depend on cooling down components.
At twenty minutes and no mention of energy points it's abstract. At six seconds and a power rating it becomes material.
Which again comes down to whether or not the full power of the plant is being used at all times. If it's not, then there's power available for something else while components are cooling down. Given the cost and size of the power plants, an abstraction that leaves unused power sitting idle is a hole that needs patching. If we assume these abstract rules reflect all power being used at all times, then they make sense. If we assume these abstract rules reflect some power is going unused while parts are cooling down - enough to warrant putting in and using a second spinal while the first is cooling - then the rules imply a setting in which admirals and ship designers aren't making every effort to take full advantage of their warcraft's potential, unless of course they install that second spinal, which the rules don't allow for. So, to justify a second spinal, we have to imagine a hole in the rules that the rules themselves don't imply. But, then w'd have to explain why ships that don't mount the second spinal aren't getting a bit of benefit from periods of increased agility during the cool-down phases, if those periods are significant enough to offer an opportunity for two spinals in play.
Which ... anyone's free to re-imagine the rules, and that can take us to some really cool places. Double-barreled spaceships would be way cool, as would tenders that had their several riders firing mesons at attackers, but the rules as written don't seem to imply that. I've actually been thinking tank-like spaceships with a ginormous turret housing a second spinal would be a better way to imagine it, if one is inclined toward that - and it's actually rather difficult to explain why warcraft can't be built that way. Terran battlecruiser Bismarck launches with a pair of C's in turret housings instead of the standard backbone-mount single-T.
I have a whole power allocation game worked out for CT/HG, along with maneuver, kinetic effects, armor being more of a thing, harsh choices with sand, EW sand, four ranges instead of two, and other stuff.
Kept on hanging up on the correlation of to-hit to design value and the damage tables. The really egregious design flaw is the destruction of maneuver drives no matter how big- that's gotta go.
Recently I decided to chuck the damage tables and work up my own. They look more like CT tables then HG, but they get a lot of the same feel and interactions, and I think I can get it down to one page of to-hit and DMs and have it work in abstract fleet, abstract ACS and maneuver ACS scales.
That sounds very interesting. "Harsh choices with sand"?