It means in NCDC is not as strong as an NAHL and a player can play there for a year and then play in the NAHL

USHL
BCHL/JuniorA
NAHL
NCDC

USHL top, and I agree Canadian Junior A next, but BCHL isn't what it used to be, still a good league, but only two teams in the CJHL Top 20, top team is 10th in Canada. Other leagues up north are getting better. AJHL has two in the top 10, and holds the #1 spot.

https://www.cjhlhockey.com/en/brooks-bandits-ajhl-remain-all-business-in-staying-no-1-in-cjhl-rankings