How much difference is there between Farrell's system and Gustard's system? I'd have thought not much. I've see us try to blitz against SH teams and get utterly picked apart once too often. If you don't get up there in time, they'll just go round you, and that's it. England were far too easy to get round under Farrell and I'm really not sure what Gustard can do to change it. Its not like our line speed was slow under Farrell at all. No matter how quick your line speed, if they're deep enough, your blitz won't work. As you say a lot of defending is deciding whether to blitz or drift - although I think we did also find option 3, do nothing at all. But once a team with good hands has quick ball, I think its too easy to beat the blitz if you know what you're doing.