Blindpugh -with the SH shoulder width offset feed the chance of a win against the head just approached zero. Too bad. Another element of the game laundered out.
It is only half a shoulder width, which is on the same order of magnitude as the "Length in line" of 280-300 millimetres of Law 2.2.
I would back the front fives I hooked for back in the (early) nineties to win an average of 2-3 against the head, and to be sure we wouldn't have lost any (ok, perhaps one or two per thirty+ games over a season).
If at grassroots, one team picks a slowish flanker to hook for them, and the other a specialist hooker (even slower, but power in their legs as well as some flexibility), then that half-shoulderwidth isn't the main issue. And it certainly isn't any worse than the feeding being skew, as it has been for over a decade now.
The only reason that the skew feed was allowed was because of the ridiculous hit being more important to manage, and we've got rid of that with the "bind-set" (despite it taking a while!).
Also, even if the ball does come back to the side that doesn't knock on a bit more often than in my heyday, that isn't necessarily a bad thing. A side that happens to have a stronger scrum due to "big slow buggers" may not win such scrums, but at least they can do their best to give the opposition bad ball off their scrums, quite legally.