Because of this, he can never enjoy the benefits from the 8 with more than 2 settlements.
On the one hand you can get your fingers burned. Look at the image below. As his first choice, the red player built a settlement above the 8 and below the 6. A couple of turns later, he realises there is an un-even number of steps between the 2 settlements. Because of this, he can never enjoy the benefits from the 8 with more than 2 settlements.