I remember Kristoffer commented on the dominions spread in dominions 2. According to him, amount of temples only affects the spread from prentender, home and profets, temples was allways using start dominion.
But then manual AND ingame 'temple info' are both wrong. The 'temple info' updates like the manual decribed, every 5 temples. With enough temples the 'temple info' shows no difference between dom1 starting and dom10 starting but in real there is a really big difference.