At the time who was the Broncos halves the year before Reynolds, Kelly, Dearden, Milford and Croft?
All of those options are struggling to just play well and stay in the team, and they might not even understand it too much at the time let alone explaining the why of things to front rowers.
Reynolds was able to explain to his front rowers why you're doing things- why I want you to hit the third man in, how it manipulates defenders and moves them where we want so it sets up two sides of the field and we can work to a short side and have two points of attack.
The Broncos forwards didn't understand the why of doing something and Reynolds can articulate that to them like only an experienced half can.
Some front rowers might not care too much, just tell me what to do I don't care why- but Reynolds is very big on knowing why we are doing something because then you can know what is coming next before it happens.