> - if there's a 6 and 8 next to each other, the third field is always a 2 or 12
At least in the version of the game that I own, if you follow the prescribed setup rules, there can never be an adjacent 6 and 8. The terrain tiles are randomized, but the placement of the numbers on the tiles is deterministic, and results in a spatially uniform distribution of the high-yield numbers.