its the nature of colonization that the fields are random in their given range per position and for every player it will give another result in fields and temperatur. And the bonus like metal on positions 6 to 10 or crystal on pos 1 to 3 is always fixed per position.
who would colonize a pos 8 planet when he would see he's getting only one of the smallest possible planets like 219 fields as discoverer on a server with already 30 bonus fields? no one - so this position wouldnt be attractive for anyone. and it would be a wasted position.