Speaking of Fallen Spire, I suspect that a low unit cap especially in regards to engineers makes it especially more difficult to survive a multiplayer, galactic capitol + extra hubs (we're talking around 9 total spire city hubs, 3 dreadnaughts) than it needs to be.
To elaborate; between the reduction due to setting unit cap to low and the reduction due to the number of co-op players, you cannot spend resources faster than you bring them in. Unlocking mark 3 engineers wasn't enough to handle demands, I had to hunt down an experimental engineer fabricator, which didn't live long.
On the other hand, fallen spire ships maintain their normal cap, and their weapons are still potent against low cap ai. And, I was definitely asking for trouble with nine cities and so many players. So I'm not confident anything actually should be changed.
In reflection, what I'd like to see (which should make a big co-op fallen spire game more viable), is that on low cap, engineers either ignore the usual cap multipliers due to scale (like fortresses, bomber starships), or get their repair/construction rates scaled up. If they do, and I'm simply not aware of this...
I find this would make attempting a silly thing like trying to produce 3 (or more!) spire dreadnaughts a lot more viable. Even with all my engineers focused on the shipyard i still couldn't outspend my hab.
On a less serious note, why not have foldout habitation centers, and foldout reactors? It's really interesting how the spire outpost foldouts increase firepower by a significant factor - but hab centers and reactors don't. Well, aside from all the coding complications and possible bugs. On top of that, just imagine the fun of everyone having +5400 metal and crystal! Everybody gets a Super Fortress! (which is looking a little neglected in the age of the Shadow) I'd be concerned about lack of balance but I'm more worried of the hunter killers and getting my co-op buddies to actually work together.