If gems are in the outer isles, then how do we balance the players who have gems on their nearest island, and those who don't? 10 gems might be too many, but giving some players a 2/1/6 tile, and others not, in territory they don't have to contest that hard for? I expect 7-9 players will end up being the only person to settle their nearest island (someone's going to lose badly in a rush, overemphasize the donut, or a crazy Pink Dot scenario works).
I do think gold in the inner section makes sense. The other option would be 3x each of gold and gems in the inner isle, and no pairs of them being in range of a single city.
For corn: Hm. If we put corn in the center, then we're going to have very few rivers in the center to limit irrigation. Is that desirable? Either pigs or corn should be in the center, and the other in the islands. I'd lean towards wider irrigation in the center, and jungled pigs, with corn on the outer islands, but either way should work. Wars over fresh water sources would be interesting (and no spies to sabotage those improvements at key moments...).
I do think gold in the inner section makes sense. The other option would be 3x each of gold and gems in the inner isle, and no pairs of them being in range of a single city.
For corn: Hm. If we put corn in the center, then we're going to have very few rivers in the center to limit irrigation. Is that desirable? Either pigs or corn should be in the center, and the other in the islands. I'd lean towards wider irrigation in the center, and jungled pigs, with corn on the outer islands, but either way should work. Wars over fresh water sources would be interesting (and no spies to sabotage those improvements at key moments...).