Peat. I agree that England had other issues in that game, and I never stated that the backrow balance was the root of all evis in that performance, far from it. However this was a debate about the merits of Robshaw as an openside, and the balance of the English backrow (not started my myself), so I didn't want to go into depth about the issues in the scrum, the balance of the second rows, Farell's goal kicking, the balance in the centres, and the creativity of the back three, which were all probably of bigger concern in that game.
That doesn't mean that there is no merit in debating the backrow selection, especially when there are fixes available for many of the other issues with a return to fitness and form of some players (Corbs, Morgan, Foden etc.), or simply picking form players (36, May, Wade, Burns etc.).
I see the balance of England's backrow as a similar issue to the balance of the Welsh midfield. Both Davies and Roberts are very decent players, and they have combined to produce some good performances and been part of successful Welsh performances, but is the balance as good as it could be? Imo, no. Introducing someone with a little more creativity (Henson, Beck) at 12 would imo enable this Welsh side to improve, with Roberts and Davies battling it out for the 13 shirt. That's not to say that there aren't other areas of potential improvement of the Welsh team, but it's one of them.
I admit that I've applied too much importance to the Wales v England game, but imo it highlighted a few issues in the backrow, regardless of other problems. Yes, they were probably hugely magnified due to the other issues, but it doesn't mean they weren't there. Similarly the poor Wales AI's highlighted issues in the Welsh team, even though they have gone on to perform well since.
Maybe the ideal 7 isn't yet available for England, and that for the time being the current combo is best selected for the big games, but it doesn't invalidate the concerns.
As for France dealing without what we're calling a traditional openside, I feel it's somewhat different. That system has always been in place, and as such their flankers are taught and develop a different type of game. Asking players who have always played with the more widely used openside/blindside combination to switch to using a left/right system is probably very difficult indeed. It's like asking a 10 to play at 9 (both have a big hand in controlling a game and distributing the ball), some can do it (again in France the positions are a little more interchangeable because the 9 has a bigger controlling role than in other countries), but most can't.