The Pennsylvania Department of Education (DOE) released a statement saying that Fordham didn't consider all the "tools and resources" that are available to Pennsylvania teachers because, unlike in some other states, they are not part of the official standards.
What you include in the standards document itself plays a significant role in Fordham's scores. They want a suggested reading list in an appendix, not a separate document. They want year-by-year standards, not benchmark standards fleshed out in a separate year-by-year curriculum document. They want examples and anchor papers in the same document, or at worst linked right next to the standards on the relevant web page where their intern can definitely find them when plowing through all this crap for 50 states. Also implicit in this is that the state ought to decide the above issues, not local schools and districts.
There is no evidence indicating that any of the above distinctions improve implementation. I would argue that it is best to keep the standards document itself as simple as possible, because you only want to revise it, at all, once every decade. You don't want to release a new version every time you switch one topic from second to third grade, add a book to the recommended reading list, or re-think the score on an anchor paper, nor do you want to be locked into only doing those things every five or ten years.
On the other hand, Finland doesn't really have a separate standards document that I can find at all. They have very simple minimal standards, that Fordham would hate if published separately, embedded in a comprehensive curriculum document.