Why there’s an abnormal amount of centre-backs taking set-pieces in the NWSL

In quite fantastic fashion, there is an abnormal representation of centre-halves on set-piece duties. Normally associated with banging in the goals from free kicks and corners, several NWSL teams instead have one of their centre-backs as a key taker of set-pieces. This begs the question we should always be asking in analysis - and that is...why?