I give up this one, it is completely won weeks now but very tiring.
First time I tried this scenario on regent, I struggled to win. This time, on Emperor, it was quite a smooth walk to victory despite huge self-restrictions, both mine and from the scenario.
From another perspective...
It's not a smooth walk, since you're not walking to victory. It would be a struggle for you to win, since you don't have motivation to try.
Extra game time for the player to show his superior human skills perhaps? Infrastructure like libraries playing a bigger role if having built early?
It definitely favors the human player to have ancient age techs non-tradeable.
The AIs will use entertainers, not use a scientist or raise the luxury slider for a bit. They also tend to overlap a fair bit in terms of research. They also put out settlers in the ancient age before building granaries. And they will use unroaded tiles a fair amount. Soren Johnson has said before that they were designed to play suboptimally in some respects.
I never understood the default of 66%. That is years of your life on a big map.
Yes, 66% is really ridiculus. Thinking a human may reach 40% and NOT be totally winning is utopic thinking..
The domination limit isn't just for human players. It's also for AI. If it were too low, then AIs could win easily and that would probably lead to frustration for the human player. I think it's also 2/3 of the council vote in the original Master of Orion.
After playing for high histographic score for the HoF several times, I can say that I do understand why and it's not ridiculous at all. If the domination limit were too small, then basically only one type of tiles would work out as best to settle. Pretty much, just grassland. If it were too high, then all tiles would end up worth the time to settle for high score... I mean have in use at 2050 AD here, not getting to the domination limit. But if it's just right, then more tile types become worthwhile to settle, while also making for variety.
Also, you aren't total winning by reaching 40%. You don't win, until/unless you get those final score scenes. No, one doesn't prove that you could have won by getting to 40%, as kaskavel's picture above shows (and I've had similar matches... having 40% of domination tiles, but not winning, even by 2050 AD). He didn't win and apparently won't ever. So, he wasn't total winning, since that requires having completed the game with a win.