On county games : last year if you recall, there was an edict that referees couldn't use YC in county games (!) I think that's a very good example of a competition organiser dictating how their competition should be refereed --- and managing to get the people who appoint referees, the Societies, to agree to that change. (I got that memo)
Yes that still is in place this season and was an RFU instruction through the proper ,management channels to Societies.
County age group rugby is a serious standard.
These age group County matches are used as selection chances for Divisional and England squads, and also with Academy scouts present.
The guidance request to keep 15 on the pitch comes from national & divisional coaches / selectors.
I respect their pov and had a good discussion with some of them at the recent Hampshire v Sussex U18 match, which had three England squad players in action.
Also the argument is that such matches (on a Sunday) should be refereed by someone two or even three levels (so Panel or Group even, not just a L6 at U18 level), with appointed ARs, and that any YC / RC player should be replaced to keep it 15 a side.
I have been to three U18 matches this season and in one case a very decent L7 referee really struggled for physical pace and game management reaction speed. His performance did slow the match up and was not good enough at the breakdown. Some coaches and parents were complaining post-match and I had some sympathy. For some of these players these selection matches are part of the Academy contract process so can make or break their future career.
Last Saturday I saw the son of an old team-mate of mine make an impressive debut at L5 at the match I was Observing. He has gone to University locally, as he was turned down by a Premiership Club for a contract after three seasons in their Academy, living away from home and at the school local attached to the academy. He is an England International at U15 & 18 levels.
He is gutted to have not made it, and it demonstrates just how competitive it is at these levels.