So I was looking at the numbers with a view of bringing the combat spirecraft (namely the Siege Tower, Ion Blaster, and Implosion Artillery) back to their originally intended space of "more individually powerful than starships, less individually powerful than golems".
Turns out that could be a bit tricky
I wonder how many of you have already noticed that a MkV Zenith Starship has 90% of the HP and 91% of the (bonus) DPS of a Black Widow Golem? And almost as much armor (5000 vs 6000)
Even compared to the Armored Golem it's got 36% of the HP and 80% of the (bonus) DPS. Though the golem has rather more armor, putting the Zenith's effective durability closer to 8% of the Golem's, but not against everything.
Granted, MkV Zenith Starships are only available from fabs (and exos), but there are MkV versions of the spirecraft too.