Just found this wee tidbit -
England are looking at ways to increase the stock of English coaches capable of taking over when Eddie Jones departs as national coach. Ritchie expects Jones to step aside at the end of 2019 – "I'm working on that assumption because that's what we based the deal on in the first place" – and is looking for "a seamless transition" involving English-born coaches who have operated outside the Premiership.
The RFU's professional rugby director, Nigel Melville, hopes to liaise with the clubs to help give up-and-coming coaches more international experience, either with England's age-group and Saxons squads, or overseas.
"I think it's been proved that just being a Premiership coach does not necessarily make you a good international coach," Melville said. "We need to work together to develop the next generation of international coaches. There are some great young coaches out there who could be fantastic coaches in the future."
https://www.theguardian.com/sport/2016/sep/27/england-twickenham-cash-australia-new-zealand
So there we go. RFU are working on it after all.