Hmmm... I have trouble believing that 40 turns of Sushi with +20 fpt equates to 400,000 gold, especially this late in the game (edit: by late in the game, I mean close to launching. You're still WAAAAY early in the game in terms of the year). First, I'm not sure that all of those pops can be converted to WBE gold. However, I do think that in order to build spaceship parts in a timely manner you have to either a) not over-whip your part-building cities or b) use Sushi to grow them quickly to max hammers. I guess a) goes against the WBE strategy so maybe b) is the only option. How big do you expect your part-building cities to be on the turn you learn Sushi? How many part-building cities do you plan to use? Do you expect to be at one tech per turn on Marathon? If so, is that building Research or could you also do it by building Wealth? Thinking about it some more, I think the only reliable way to grow your part-building cities to ~20 pops so early in the game is with Sushi, even if you didn't whip them too hard. It's hard for me to think in terms of this game because I typically don't have to think about growing my cities until ~1000 AD. You have to do it pre 1000 BC!!! So maybe Sushi is a must just to be able to build the space ship in a timely manner but how much you end up spreading Sushi could be open for debate/optimization.