Can I just boost the 10% faction and the others (including MY faction) will all lose a little till the war?
You
can. But, that 10% faction, since it owns an asset, will go to war with one of those 20% factions first. That, or as your faction drops, your (35%) faction will go to war with one of those 20% factions.
This is presuming the 20% factions aren't in a conflict
Same with regards to expansion, will everyone drop as MY faction gains or will I have to get more...creative?
With no other actions, correct.
Regurgitating the maths I've done before, let's pretend there's 100 points in the bucket (for simplicity's sake). That is, 1% inf = 1 point. We start with :
35, 20, 20, 10, 5, 5, 5 (= 100)
Assume you do 5 points of work for your faction. This makes it:
40, 20, 20, 10, 5, 5, 5 (=105)
Normalising, we get:
38.10%, 19.05%, 19.05%, 9.52%, 4.76%, 4.76% (=~ 100) [1]
Your action result in your faction gaining influence, by stripping some off the other factions. Let's call this Result 1.
But watch what happens if we do the same 5 points of work for your faction, and 5 points of "negative" work for, say, one of the 20s (e.g selling for a loss, murderhoboing, failing missions). We get:
40, 20, 15, 10, 5, 5, 5 (=100)
This is already normalised, and thus is the new result. That's not some fancy mechanic, it's just the way the maths works. Basically, you strip 5 points worth of influence off the other factions, and the other faction "distributes" 5 points of influence to the other factions. But because it happens in a single calculation, rather than one after the other, it's virtually a direct exchange.
The three strategies which arise from this are:
1. If you want to increase a faction, but don't care where it comes from, just work that faction.
2. If you want to decrease a faction, and have that influence go to a specific faction, hurt the faction you want to decrease and help the faction you want to increase
3. If you want to decrease a faction and don't care where it goes, just target that faction with negative effects.
2 might seem like a convenient mathematical outcome, but if you're suffering from diminishing returns from having a high influence, it's actually a great way to overcome that problem. Of course, it can only go so far if your target faction only has a percent or two of influence.
[1] This is how factions can "creep" a little between ticks without any action; they don't exactly equal 100 and have to re-normalise.
EDIT: It's worth noting, I've ignored two things here:
- Diminishing returns; there's an effect beyond the natural effect of this system which, if you look at some of the graphs from Reshaping the Simulation and other research by Commanders, is quite a stark effect
- What happens in the zero-case... if a faction has 5 points and you hurt them for 10. My working assumption is each result has a "Result or 1 if Result < 1" condition, but i've never validated that.
