Actually, what should be the expected planets a player takes? I've been assuming that because the CSGs make you take 8 worlds, that 10 to 12 worlds is 'expected'
That's kind of what I'd expect at diff 9, yea.
But that brings up another question: how many planets do you actually need to take to win? I think CSGs are actually masking a problem here: the player has the actual force-of-arms to win after taking... what, 3 planets? 2? Without the deepstriking rule could you win without taking a single planet? You're just forced to take down the CSG network because nothing can kill an invincible home command station.
I played a 9/9 game back in the AS beta without CSGs, using 2 starting homeworlds, where I won without capturing another planet. If there was no deepstrike, I wouldn't have killed any AI command stations. I did it once with Champions, then once without. It took a long time, and that was pre-Reserve, so I'm not sure I could do it again today... but I suspect better players than I could.
Was it fun? Not really. I spent a LONG time rebuilding between each cross-map suicide wave. Once I'd neutered a path to the AI HWs, it wasn't even in doubt. Just grindy. That's the reason I almost always play with CSGs on - it makes the game more challenging.
But if we ignore CSGs, how many planets should the player need to take before being able to kill the AI? Players who are very skilled at doing more with less like Diazo and Faulty would be able to win with fewer systems than players like me that specialize in defense and 'persistance'. That makes it really a matter of skill and style.
Personally, I think I would like to see the human strength required to be somewhere around 50 times the original starting strength. (That's counting a cap of Mk II as 2 caps of Mk I, etc).
That basically means getting 4 ARSs and unlocking all ships to Mk II, plus 2-3 Mk IIIs, a few starships, and maybe a Fab or two.
Knowledge wise, that works out to about only 25,000-35,000 K. Do we think this is enough strength before the game is winnable? Should the AI HWs be hard enough to basically REQUIRE multiple Mk IV fleetships or starships?
(yes, I know Mk II =/= 2 Mk I. It looks Mk I equivalents actually goes 1 - 3 - 4 - 6 - 7.)
Truth be told, as long as the game is balanced enough that the theoeretical required strength is not so high that the AIP becomes too hard to handle, then I don't really mind where the balanced point is.
If you only need 20,000 K to win on Diff 9 (or Diff 7, for that matter), then there's the problem, right? Of course you'll go low-AIP, why wouldn't you?
One of the things I noticed looking back at earlier versions of the game, was not only that AIP was so much higher ("400-600 by the end of an 80 planet map"), but that there was so much more Knowledge available (20-30 planets worth). Since then, costs for some things have come down (Starships, from 15,000K to 4,000K) others have gone up (Mk I -> Mk III/IV fleetships went from 7,000K to 8,500K). At the same time, there's now more available to spend Knowledge on.
If K was made less available, even for a lower AIP rise in exchange, I think I would find myself playing with even fewer unlocks. Even in Fallen Spire, 33% additional systems to take adds up.