Connery was a navy man himself:
In 1946, at the age of 16, Connery joined the
Royal Navy, during which time he acquired two tattoos. Connery's official website says "unlike many tattoos, his were not frivolous – his tattoos reflect two of his lifelong commitments: his family and Scotland. ... One tattoo is a tribute to his parents and reads 'Mum and Dad', and the other is self-explanatory, 'Scotland Forever'".<a href="
https://en.wikipedia.org/wiki/Sean_Connery#cite_note-22"><span>[</span>22<span>]</span></a> He trained in
Portsmouth at the naval gunnery school and in an anti-aircraft crew. He was later assigned as an Able Seaman on
HMS Formidable.<a href="
https://en.wikipedia.org/wiki/Sean_Connery#cite_note-23"><span>[</span>23<span>]</span></a> Connery was
discharged from the navy at the age of 19 on medical grounds because of a
duodenal ulcer, a condition that affected most of the males in previous generations of his family.
and a bit of a brawler:
While in Edinburgh, Connery was targeted by the Valdor gang, one of the most violent in the city. He was first approached by them in a
billiard hall where he prevented them from stealing his jacket and was later followed by six gang members to a 15-foot-high (4.6 m) balcony at the Palais de Danse.<a href="
https://en.wikipedia.org/wiki/Sean_Connery#cite_note-FOOTNOTESellers199921-36"><span>[</span>36<span>]</span></a> There, Connery grabbed one by the throat and another by the biceps, cracking their heads together. From then on, the gang treated him with respect and he had a "hard man" reputation.<a href="
https://en.wikipedia.org/wiki/Sean_Connery#cite_note-FOOTNOTEYule199232–33-37"><span>[</span>37<span>]</span></a>
so despite his youth he had enough lived experience to be convincing on screen.
Roger Moore served:
At just 18 years old, and with the Second World War newly over, Moore was conscripted for Britain's mandatory national service. In September 1946, he was commissioned as a second lieutenant in the Royal Army Service Corps and eventually became part of the military's Combined Services Entertainment division. Rising to the rank of captain, he was stationed in West Germany, where he oversaw a depot that helped coordinate entertainers performing for British troops moving through Hamburg.
David Niven served:
But before that, beginning in 1928, he attended the Royal Military College at Sandhurst, where he developed the polished "officer and gentleman" image that would later become one of his trademarks. Hoping to join either the Argyll and Sutherland Highlanders or the Black Watch, he jokingly listed his third preference as "anything but the Highland Light Infantry," objecting to their tartan trousers instead of kilts. Ironically, upon graduating, he was commissioned as a second lieutenant in the Highland Light Infantry on January 30, 1930.
George Lazenby served in the Australian Army, apparently rose to Sergeant in the Special Forces and was a martial arts instructor.
So these more youthful men had at least a bit of Bonds actual background which could inform their performance. If they hire a vet in his late 20's then I think it could be ok. Otherwise I think it s a GRAVE mistake as that youth will work against him.