To be fair he would of not needed a big army. 11 trebs, 8 WE and 5 knights. He didn't lose a single unit. That is how bad the AI were here against a tech giant. WE 8x50=400. Trebs 11x80=880. 1280 hammers used for army. Plus more hammers for 2 knights and a musket or so for Greeks. So investment of 20 units to gain 15-20 cities late games yields nearly +2-3k science from research and cottages a turn!. Most of these units would of been whipped and the cities would of regrown quickly. So you can ignore this 1280 hammer figure. Especially if he chopped from captured cities.
At 1240ad he was churning 1200 more beakers than me at 1200ad. I was in a golden age at that point. So I can imagine his beakers being even higher during a golden age. 5k plus come late game? At this point in Bibor game you had around 1200 at 70%/1500 at at 80% research a turn. So 1200/1500 beakers a turn ahead. He had communism at this point plus an empire of 28 cities. The maths is simple. An empire double the size can and could generate twice as many hammers/beakers. Especially large captured Ai capitals with flood plain cottages.
The whole point of this exercise was to see how you could play peacefully for a space win. If you were not worried about finishing dates then possible. On a normal map with 6 AI chances are you would not have land for 12 cities. Or land as good as this to cottage with a financial leader. On mine and his game it was clear early on the AI were struggling due to human players who knew how to exploit such a strong start.
On a normal immortal game you might end up with land to build 6-7 cities. Emperor maybe higher as AI is slower to expand. Space race with a smaller empire could be possible but you would need Ai to trade techs with to speed it up. Plus 3-4 very strong cities. I think most would struggle with a very slow end game. I am sure there are HOF games with such victories.
This is why players mix conquest with space. It's so much quicker. It also shows why a hammer economy can and is so strong with a a large empire.
I think that your analysis is spot on
. If nothing, comparing our saves shows exactly why more land means a faster space date, all the time, no exceptions. In the case of communism once you have 3 TRs every city pays for itself the moment it's founded, in terms of commerce. And every city can rapidly reach over 50 hammers a turn with a forge + factory (that's auto-powered because TGD). At that point, every city that's even halfway decent will output many, many more times hammers and commerce than it took to build or capture it. In fact building that decently-sized army to capture even
one capital + another city would've been worth it. I can't overstate the advantage that having more land in this game brings. And in the case of corps...well you gotta collect corp resources somehow.
Side note: halfway through the game I noticed "new random seed on reload" was checked and decided to abuse it...hence the 0 units lost. But if I hadn't, then I would've lost perhaps 1 treb every 1.5-2 cities (after bombarding CR2 odds against maces were ~70%, longbows were ~75%, against swords 90%+, increasing drastically after every fight with collat). I did this for aesthetic purposes, as I've always wanted to play an optimal space game with 0 units lost for whatever reason...and this seemed like the perfect chance. So I guess...x1.5 or double the cost of trebs to get a more realistic appraisal? But even if I had to build twice, or 3 times as a big an army, the benefit of even moderately more land pays it back in very short order. And I got a
lot more land. Besides, my production base was so high that even doubling my army size would've been like breathing slightly harder on an AI to get it to topple.
One more thing - the early game was also important. I think you and I took a similar approach in cottaging everything and chopping/whipping settlers/workers, which is the way to go about a map like this. My policy is that on maps like this, every river tile without a resource must have a cottage, especially if you're fin (unless food is really poor - and it's not here). I probably got slightly ahead even before the conquest because I did the 1-pop settler strat, traded for a few techs that you researched, Oracled metal casting, and whipped more mercilessly; IMO 6-3 settler whips are the most efficient as your growth is halted for the least amount of time, and should be done whenever possible, even if you have to whip away cottages (whipping away mines is almost always OK). Hence, I was able to grab the bananacorn and dye sites before Spain.
from Expansive and +3 
. I had to use the overflow trick* to complete the stasis chamber in 3 turns and life support in 2 turns; that was some serious nail-biting micro. Other than that, though, smooth sailing in the endgame.
