I think Roach is certainly part of the problem, he's been awesome around the park but he's a lightweight hooker.
On your own ball, having a smaller hooker isn't really a handicap if you're striking, because he can't contribute to the push anyway. It is a factor on your opponent's ball when you're talking the hooker being a third prop at this level.
If your scrum is dominant enough to step over the ball, and not bother with striking, then the size of the hooker is not an issue.
If your second row and props are good enough, then your hooker can strike as the other side come under pressure and mess up their ball. Fave tactic: kick it into the opposition's legs and hope it bounces back to you.
How do you determine who is the weak link between the THP and TH lock? What effect does the flanker have - Does Hooper always pack openside or does he sometimes pack blindside? Serious questions.
Also, I think he usually plays LH lock with Skelton at TH lock this year, or am I wrong? I know he might have shifted for this game. Scrum has been alright with Skelton and Dennis. Is Roach part of the problem?
First thing to keep in mind that most of the power in the scrum is the second row.
From there, its mostly a process of elimination - Dennis played the game at TH lock and we were getting pushed up on that side mostly. This indicates to me that Dave hasn't got the sheer grunt required to support it, because that is where you get attacked. At the same time, Robinson was also getting a hammering because Chapman at LH lock wasn't great. If your second row is working well together, your scrum doesn't shift, your hooker can strike, and you do this all in syncrhonisation.
If Simmons is going to be picked at TH lock - and his form there for our scrum suggests nothing else - then Dave's best chance is as the blindside who fills in at LH lock when things go to shit, or a benchie when we want to play a fast, impact game.
Which will NOT be against Wales or England.