I can't know obviously - but that's a good guess.
People obsess over "systems" but in my experience it doesn't work as smoothly as people think it does. It's great for language/comms around things that are standards (shapes, naming your sets, places on the field, etc.) and it works really well for when players come up to the top team, but for how you want to play they don't translate down to lower grades because that is usually personnel specific. I want Riley Pollard to be the best version of Riley Pollard. I don't want him trying to match the style of the NRL halves.
If I was the feeder coach in this situation I'd go with "keep it simple" and "let them play".