Two abysmal displays against New Zealand in June were further evidence the beaten World Cup finalists require urgent attention behind the scrum.
Geraghty blossomed under Smith at London Irish is convinced the influence of England's new attack coach will become apparent during the busy autumn schedule.
And while the England fly-half insists the RBS 6 Nations finale against Ireland was encouraging, he admits the element of surprise has been lost.
"People see London Irish as a team that tries to play an attacking style. They often don't know what we're going to do next," he said.
"In international rugby you need that. Maybe that unpredictability has been something that has been missing from England over the last few years.
"Defences are so tight nowadays that you need something different.
"That unpredictability was there against Ireland in the 6 Nations but obviously we need to do more work in this area.
"Brian will be looking to take it on a few levels. He will change things around and introduce new ideas that haven't been seen before."
Smith's reputation soared during his three seasons at London Irish where he shaped the team into the most entertaining in the Guinness Premiership.
The 41-year-old, born in New South Wales, was capped by Australia and Ireland during a dual-code playing career but Geraghty insists his coaching philosophy is influenced by his roots
"Brian is always looking to keep the ball alive, always looking to play through the defensive line and get the offloads," he said
"He has a very Australian mentality in his approach. It's not about head down and running, it's about keeping the ball alive and looking for support.
"One of the easiest ways to break through a defence is to get a late offload.
"Defences are so tight nowadays that you do need something different to break them down.
"Hopefully England will have that edge to their attack now that Brian has been appointed.
"When Brian joined London Irish three years ago we were the lowest scoring team in the Premiership.
"We hadn't registered a try-scoring bonus point for almost a year but in the first game under Brian we scored four or five tries."
Geraghty is sure to profit from Smith's presence in the England camp as he seeks to add to the two caps won during the 2007 RBS 6 Nations.
Frustratingly, injury has restricted the gifted 21-year-old's chances since making a thrilling debut against France, but November could be productive if he stays fit.
Tests against the Pacific Islands, Australia, South Africa and New Zealand await and with Danny Cipriani still in the treatment room, he is sure to get his chance.
"November is a long way off but I'd love to be involved," said the fly-half, who is also comfortable at inside centre.
"I want to stamp my authority on things because it's been a while since I was last involved.
"One of the targets I've set myself is to get fit and stay fit. I know I'm a good player and the coaches know I'm a good player.
"I just have to show that from the first week in September so that I'm ready to take on the best in November."