The movie Saving Mr Banks stars Tom Hanks as Walt Disney (foolproof casting) and Emma Thompson as P.L. Travers, the creator of Mary Poppins — who, as most people don’t know, was born in Maryborough, Queensland. The makers of Saving Mr Banks were concerned (needlessly, it turned out) that Walt Disney Pictures might want to tone down the portrayal of their founder and cult figure. When the film premièred in Australia on Boxing Day, local audiences had a different question: can Emma Thompson do the accent?

Australians care about such things. Meryl Streep is still disparaged for her 1988 role as Lindy Chamberlain in Evil Angels, which she delivered in a studied, tonally correct mid-Tasman accent. Unfortunately, accents are supposed to sound effortless, not studied.

The accent is just part of it. Though we take pride in our own actors’ ability to portray other nationalities, we are sceptical about non-Australians playing iconic Aussies, even if their nationality is not one of the ‘iconic’ things about them. Few nations are so precious. Even America’s stridently patriotic film community gave an Oscar to Daniel Day-Lewis, an Irishman, for playing one of their heroes, Abraham Lincoln.

Still, non-Australians will bravely play famous Aussies. Three weeks ago, Forbes named The Fifth Estate, about Wikileaks founder Julian Assange, as the year’s biggest box-office turkey. This must be great news for Assange, who protested against the film even before it premièred as the opening film of the Toronto International Film Festival (TIFF to its friends) in September. Obviously, he hadn’t yet seen the film, but had already dismissed it as lies, pleading with the English actor Benedict Cumberbatch not to make it.

The Fifth Estate is an accidental sequel to the Australian flick Underground: The Julian Assange Story, which screened at last year’s TIFF. Underground, made as a telemovie for Network Ten, was about Assange’s teenage years, when his crusade began. While not suggesting he was flawless, it portrayed him as a heroic idealist.

No such luck with The Fifth Estate. Cumberbatch, Britain’s thespian-of-the-moment, seems like an amiable chap. However, he mainly plays villains. Even his most popular heroic character, the great detective in the television series Sherlock, is cold and impersonal, too arrogant to treat mere mortals with any civility. It made him an obvious choice for Assange — or this version of Assange, at least: manipulative and egotistical, with dubious ethics and few social graces. Assange’s protests against this film might have been pre-emptive, but his fears were realised.

Still, Cumberbatch managed something that eluded Meryl Streep. His Australian accent seems so natural that, when I saw the film in Toronto, it was half-finished when I suddenly thought: ‘Hang on, he doesn’t usually talk like that.’

Beyond the accent, however, is he Aussie enough? Does he play one of the world’s most famous living Australians with the right amount of anti-authoritarianism and derring-do that Assange seems to possess, and that we like to see as typically Australian? Well yes, but Assange still doesn’t come out looking good. This time, of course, most of us probably won’t mind. Assange was infamous well before the movie was released.

But while a contentious figure like Assange needn’t be portrayed as a gallant knight — provided the accent is right — perhaps we can object if a non-Australian is cast as a true national icon, someone who represents what it means to be Australian (whatever that might be).

At TIFF, you didn’t need to go far to see this. In The Last of Robin Hood, about the final days of Errol Flynn, the American actor Kevin Kline played the great Australian movie star. Despite his reputation for athleticism, Flynn lived a notoriously unhealthy life, so that when he died at age 50, he had the body of a much older man. That’s presumably why Kline, now 66, was cast.

Kline actually looks like a dashing swashbuckler — he also played the silent movie star Douglas Fairbanks, the Flynn of his era, in Chaplin (1992) — but he was born in the wrong time. When action men looked more like Stallone and Schwarzenegger, Kline was doing suburban dramas like The Ice Storm and knockabout comedies like A Fish Called Wanda. ‘Elegant, debonair and with mischief in his eyes, Kline always has been and remains the only conceivable choice to play Flynn,’ suggested the review of The Last of Robin Hood in the Hollywood Reporter. This was a little unfair to the English actor Jude Law, who was perfectly good playing a younger Flynn in The Aviator (2004), but the point was clear.

Kline makes no attempt at an Australian accent — which is historically accurate, because neither did Flynn. Flynn tried to downplay his Tasmanian origins, and would be baffled by those today who try to claim him as an archetypal Australian. Flynn chose to speak in a refined English accent. That’s fortunate, because Kline’s previous attempt at an Australian accent — as a media mogul in Fierce Creatures — was awful.

Flynn was the most world-famous Australian of his era, so his rugged charm and sex appeal became part of the national stereotype — one that we were happy to accept. Nonetheless, he was never a ‘typical’ Australian. In this otherwise lackluster film (still awaiting release), Kline brings his charisma and recklessness to life, but he plays the celebrity, not the Australian. Still, few Aussies would complain.

No mean achievement. Like a handful of all-Australian idols — Bradman, Ned Kelly, Dame Nellie Melba — you shouldn’t mess with Flynn. Recently, Dame Kiri Te Kanawa played Melba in the television series Downton Abbey. She’s a Kiwi (and today’s answer to Melba), so it’s close enough.

But what of Thompson as Travers? Based on the trailers, her accent has no trace of Australia. (Admittedly, Travers had lived in England for many years.) Still, she is portrayed as such a humourless, fun-hating figure that we should be happy for her to sound British.

Whatever it takes to play an Australian, non-Australians should be welcome. Until Hollywood casts Matt Damon as Bradman, let’s sit back and enjoy.