I don't agree with you that the GA (or any wonder) counts as that many tiles, because what are you replacing it with?
The impact on the Spire/Tourney formula could be less by not having it, but I showed above that it would cost more tiles to replace it with regular residences. Should I be lucky enough to win enough Magic Residences, the formula would be:
163,350/1408=116 tiles of Magic Residences required to replace the population, so 116/24=5 Magic Residences (rounded to whole residences).
The culture 5*13,700=68,500 divided by 3000 culture per tile = 23 tiles of culture for a total tile spend of 116+23=139 tiles, or 5.56 expansions. I'd save 9 tiles from the GA, so 130 tiles, equal to 5.2 expansions.
But the comparison isn't with expansions, because that would cost diamonds to buy at an escalating diamond cost if I were to replace the reduced tile efficiency with expansions. If I removed the GA, I wouldn't get the extra space, I would have to spend 130 existing tiles to replace it.
Even if the tournament is now easier, with no extra expansions, I would have to delete 130 tiles of other buildings to find space for the population replacement options. I'm likely not removing Barracks, Training Grounds or Mercenary Camps from reduced troop needs. I could remove manufactories, but would have to remove 130 tiles worth, or about 5 manufactories. That in itself then saves population, so there is an equilibrium somewhere lower than 130, but I'm now also less productive.
At CAL 10337.5 vs 10845.4, what is the actual cost impact on tournament or spire? Would it offset the reduced resource production I now have?
Total AW Levels 350 Tournament Costs
Total AW levels 318 Tournament costs. At round 16, where I would likely start purely catering, T1 reduced by 3000, T2 by 2000, T3 by 2000. Each marble manufactory that I had to remove produces 13,122 marble in 3 hours, which I can have running all week. Given all costs reduce, including gold which we get from GA, I could reduce Orcs or Mana production too, balancing between all requirements, but I still think I'm worse off.
You are right that the gold and impact on other wonder productions also make it worthwhile, but for now I will stick to ranking it no 1 on population per tile.