They used to do this 60 years ago when I was a young 'un over there. If you were ahead by so many, (I forget how many) the forwards of one team had to play with the backs of the other in the second half, with the score at half-time being deemed the final score.
I played for a gun team called Sydenham and the coach was ropeable if we passed the limit at half time. Then in the 2nd half we would play our best.
Our coach was not touchy, feely and neither were the lads. When my lads played for Narrabeen, Newport had this gun team. They had this monster forward called "Big Ollie" and every possession was a score to somebody.
Their coach had a rule that no boy could score more than one try per match. It taught their lads positive teamwork.