This trade problem can't be tackled by singling out logistics. The work required to balance all the races is a nightmare by just changing one element of the game. The change has to be broad which includes military units as well. 

E.g advents weak economy is made up by having high dps units, shields and culture. Two things can happen:.

Advent become unable to deal with other races and require even more firepower, shields and hull or the other races fall victim to there units and can't counter that with a better economy.

That would be the ideal change in my opinion, but I have no idea how you could implement that change with just a mod...barring that, I don't think disrupting trade is particularly viable...

I have toyed around with the arcova's timed explosives and the seeker's martyrdom to make the abilities target and disable structures for short periods of time....however, the problem is that if a planet has multiple trade ports, disabling one isn't going to break the longest trade chain...to make these abilities effective at disrupting trade would invariably make them OP against factories...furthermore, the Vasari have no equivalent ability on their scout (and they already lack an anti-module ship)....

I don't think filling a planet completely with research structures is a realistic situation...for one, you will almost always want at least one trade port to develop your trade chain...that alone means you'd be looking at 5 vs. 6 labs...add one more structure (such as a capital ship factory, or a culture center, or another trade port/refinery), and now you are looking at 4 vs 4 labs...

For asteroids, desert, and ice/volcanic, you wouldn't need anything beyond one trade port to make both systems comparable in the number of labs you can support...

Yes, in theory it can be easier to get labs but only if you don't make trade chains (something I find highly unlikely)...for all practical purposes, fielding labs is more or less the same...

I do agree that fielding labs should not be easier, especially when (if anything) many technologies need to be buffed (mainly the civ trees)...in practice though, I don't see this new system allowing that to happen...

I'm working on the assumption that refineries are modded to equal trade ports (more or less)...how exactly that will occur is irrelevant, but on the basis that they are equal in economic power, I don't see any reason why they should differ in the number of slots they use...

As far as I'm concerned, if refineries were buffed to the level of trade ports, there still would be a problem of diminishing returns...

I could...but my primary concern is diminishing returns...clearly more planets should equal more economic power, but how much more?  What I have a problem with is that one planet can make the difference between a near broke economy and a booming economy due to a fixed number of mandatory structures...if I have six planets vs. your five, and my sixth planet is a desert, that is 9 extra trade ports I could build (vs. 5 under the proposed system)...it is my feeling that starting positions and randomized planets are already enough of a crap shoot, and I feel this is one way to mitigate that...

I am considering changing the slots needed for capital ship factories and culture centers to one each (equivalently, culture centers could be made more powerful so I'm not concerned with that yet)...however, the core change is the difference in logistic slots between factories/labs and trade ports/refineries...

Why should trade be nerfed?  It's a long-term investment that comes at the short-term cost of having fewer ships and combat upgrades.  A better subject would be to discuss whether or not a specific race's trade ability needs to be nerfed or buffed.

I agree with this...which is why I still think there should be a trade length bonus (though I'd advocate a slightly smaller bonus)...

I think this is what I'm trying to say, and I apologize for being unclear earlier...I'd say you've provided a more eloquent description of my problem...

I still do want to have diminishing returns on an empire wide basis...right now though, I think the trade length bonus outpaces the decreasing allegiance such that additional worlds actually increase economic efficiency...this is a trend I'd like to reverse...one clear way to do this is to reduce the trade length bonus...reducing the max number of trade ports per planet also accomplishes this because trade becomes less important relative to extractors and tax income (two things affected by allegiance)...

Hmm....that is an excellent idea, and certainly would give the desired effect...I'm not sure how I feel about it yet though, as it still doesn't account for mandatory structures...thanks for the idea GoaFan, that is good....

If a faction inherently has bad trade (AKA Advent), and the importance of trade is reduced, then that faction relative to the others would be more economically competitive...not a direct approach, but on the premise that trade is too powerful, one mechanism can be used to solve (at least partially) two problems...

Of course, if you don't think trade needs to be changed universally in any way then these propositions are moot....

Personally, I don't think Advent need a trade buff, especially if trade/refineries as a whole lose some of their importance relative to other forms of income...what does need to occur is a buff to resource focus...however, that is entirely independent of how TEC/Vasari refineries work (which I think need to be more competitive with trade ports)...

Advent "refineries" work a lot differently than other refineries...for one, Advent do not have two different structures that have different costs (one variable that is very relevant in an economic analysis)...additionally, you have different probability distributions to work with....you know for certain that any given planet will have 2-4 extractors, making it easy to calculate a good value for resource focus...however, refineries pull from all nearby extractors (a number that is a lot more unpredictable and has a high variability)...

They really are two separate issues...the real issue is that we are in an area that is highly controversial...some people think trade spamming needs to be nerfed, some think refineries need to be buffed, and some think there's no need for any change (if refineries aren't as good, then you simply don't build them)...

So, in effect we have a philosophical difference that makes any sort of consensus or agreement impossible...personally, I'd think it'd be great if equal numbers of refineries and trade ports was a viable strategy...

I've given up on ever trying to get consensus for anything, and simply try to get constructive feedback on things I'm implementing for my own personal use...

Under the proposed system, structures would only need 1 or 2 slots, which is why upgrades only add 2 slots...

If culture centers and capital ship factories were also only 1 slot, would that help?

What about what I said, quoted below?

I think I may be confused then on what you mean...what exactly do you mean when you say it "trivializes logistics planning"?

Actually Zeta, I'm also curious as to what you are trying to say as well...I thought I understood and then you posted again and now I'm not so sure...

It seemed like you were saying have all structures use x number of slots, with x being divisible by 4....I'm guessing that's not what you meant though, because that's how the game already is....

Agreed.

I understand what you are saying now, and I do agree it is a little odd...it may be a convention that was used in a beta or very early version of original sins when (perhaps) not all logistics structures used 4 slots...