not a teacher
A "champion" has two meanings:
1) someone who is triumphant over others, who is very successful in a specific field
or, as you have quoted…
2) "someone who publicly supports or defends a set of beliefs, political goals, or a group of people", in other words, an advocate.
I believe soothingdave is saying that because of its use of "champions" in a context where "advocate" would be less ambiguous, the passage is not well written.