Much has been made of Australia's supposed batting frailties but they can count on the ever-dependable Smith, who will line up at No.4 and lead the side in the first Test in Pat Cummins' absence.
The 36-year-old has 12 centuries in 37 Tests against England, while he is the only two-time recipient of the Compton-Miller Medal after averaging more than 100 in both the 2017-18 and 2019 series.
England managed to keep him relatively quiet in 2023, when he averaged 37, and the experiment of him opening the batting last year backfired but he is back to churning out the runs from the middle order.
Finn, the former England fast bowler who starred in the 2010-11 Ashes series win in Australia and who is now working as a TNT Sports pundit, said: "I'd say he's still at the peak of his powers.
"He has that desire and hunger to score runs and is probably the most influential person within Ashes series of the last 20 years, if you think of the amount of ridiculous performances that he's had.
"He loves the pressure and environment of the Ashes and he will be determined - this could be his last home Ashes - to make sure that his memories of it are positive from a personal and team perspective.
"I would be very, very wary of Steve Smith if I was England."
Smith went 23 innings without a century between June 2023 and December 2024, but has four in his last eight Tests during a period where he has also passed the 10,000-run mark in the longest format.
Smith marked his first outing in the Sheffield Shield a fortnight ago with 118 for NSW and made two fifties this week in his final matches before the first Test, starting in Perth on November 21.
Finn, who dismissed Smith three times in five Tests, said: "He seems to have found peace within his batting. He's moved back to his favourable position of No.4.
"He doesn't seem as obsessed with cricket as maybe he used to be, which I think at his age is something that's healthy, to keep that fight and desire when you're out there in the middle."
Finn believes one of the most intriguing subplots of the upcoming series will be how Smith fares against Jofra Archer, who has never dismissed the Australia batter but famously hit him on the helmet with a 92mph bouncer at Lord's which led to him missing the following match with concussion.
"It could be a pivotal moment within the series," Finn added. "But what I think we're going to see is both players believing that they can win that situation, which will be riveting to watch."
