Mark I Spire Maw has 2.100.000 health
Mark I Spire Stealth Battleship has 1.920.000health
Mark I Spire Tractor Platform has 1.600.000 health
EDIT: The lowest health combat Starship (except Riot) has 10 million health.
Mark 1 Spire Maw: Can easily hold inside of it 50 fleet ships, making it more than 50 times greater in size than any 'edible' fleet ship. It also only has a cap of 5.
As far as the low health combat Starships are concerned, the Raid only has 2 million health. Of course, like the Riot (and Maw, Torpedo Frigate, Stealth Battleship, and Tractor Platform) it is a special function combat ship.
Finally as far as resource cost for each of these is concerned (and build time)
Raid: 82k resources 11:07 Cap 3
Riot: 80k resources 06:57 Cap 4
Maw: 25k resources 03:29 Cap 5
Stealth Battleship: 22k resources 02:14 Cap 5
Tractor Platforms: 16k resources 01:40 Cap 5
LTF: 33k resources 00:31 Cap 8
Triangle ship comparison for baseline:
Fighter: 165k hp .4k resources 00:02 Cap 96
Bomber: 156k hp 1.6k resources 00:12 Cap 96
Missile Frigate: 156k hp 1.2k resources 00:09 Cap 96
Fleet ships have a few properties in my mind:
Expendable/easy to replace
Builds quickly
Cheap
Lots of targets to split enemy fire/wastes enemy's higher power shots
Capital ships have a few properties in my mind:
Expensive/you will want to protect these
Takes time to build, not first on your list to start
Suffers more from very high damage enemy firepower
Tractor Platforms are 10x the cost of the most expensive triangle ship. Lighting Torpedo Frigates are 20x that cost. On the reverse they are 1/6 and 1/3 the cost of the cheapest starship.
Lightning Torpedo Warheads take roughly 3x the time to build than the slowest triangle, however the other 3 are much longer and more in line with starships.
A single powerful shot that can one hit any of these ships will take out 1/5 of the Spire's firepower, 1/8th of the LTP's, 1/4 of the Riot's, 1/3 of the Raid's, or 1/96 of the triangle ship's.
I understand why the spire "fleet ships" are so large. They don't do anything small, but from a human standpoint they aren't fleetships, they are inline as small starships.
Autobuilding: These ships actually can bankrupt an early game economy on their own. This means you either manually add and remove them as necessary from your docks, build more docks just for them with control group limits, or just deal with the bankruptcy when you lose them. It literally can interrupt your economy unlike almost any other fleet ship if put on autobuild. Starships do the same things, but they have a separate dock that can be toggled and is already required.
I'm not asking for a change in balance or nerf, just change the classification and place you build them at. Perhaps add a new tab for small/special purpose starships on the starship constructor. As for the Spire "fleetships" just imagine that despite them being used as such by the Spire, your own fleetship docks aren't prepared to construct such a large vessel.
edit: Other ships forgotten:
Spire Blade Spawner: 16k resources, 1,050,000 hp, 01:07, Cap 5
Spire Railcluster: 18k resources, 3,350,000 hp, 01:24, Cap 5 (Actually has more hp than Riot Starships)
Tackle Drone Launcher: 33k resources, 1,240,000 hp, 03:04, Cap 8
Zenith Medic Frigate: 8.6k resources, 1,110,000 hp, 05:12, Cap 8 (These last two don't fit all of my criteria, I list them because they fit some)
Zenith Reprocessors: 4k resources, 1,860,000 hp, 00:17, Cap 8
At what point do we draw the line and say X is a starship and Y is a fleet ship? So far the only line I can see is "Cap <5" however this feels very arbitrary to me, and I feel it excludes some ships which should be starships.