Anyone would be silly to disagree with this.
We go into some deeper reasoning back in this older blog post (https://tmblr.co/ZrRYjxTJ6zw9) looking at arm swing and leg swing and pairing of pelvis and shoulder posturing and how clean pelvis function parlays into upper body function in softball pitching.
“Proper utilization of the kinetic chain allows for efficient kinetic energy transfer from the proximal segments to the distal segments. Dysfunction at a proximal segment may lead to altered energy transfer and dysfunction at more distal segments,”
Lower body conditioning may cut upper body injury risk in softball. -Hank Black