From chairing Ipswich Town to leading the project that created St George's Park and later overseeing the Football Association's advisory board for England's national teams, he has enjoyed a unique view of the modern game.
Yet when asked about Gareth Southgate's legacy, Sheepshanks does not begin with finals or semi-finals.
He begins with culture.
“I think Sir Gareth Southgate deserves huge credit for what he's achieved,” Sheepshanks tells Football Presse.
England reached two European Championship finals and two World Cup semi-finals during Southgate's eight years in charge, while the wider England pathway has flourished since St George's Park opened its doors in 2012.
For Sheepshanks, those achievements are no coincidence.
“The first reason for building St George's Park was a home for England teams. I would say that first reason has largely been ticked because we are regularly now getting to finals and semi-finals.
“The women's team have won the Euros twice. The under-21s have won twice under Lee Carsley. I mean, it's really fantastic.”
While results matter, Sheepshanks believes Southgate's greatest contribution was transforming the environment around the England squad.
“There was a terrible sort of factions of players from Manchester United sitting in one corner, Chelsea in another or whatever.
“I'm probably exaggerating, but it was true.
“And Gareth Southgate's the one who really broke that down, and Thomas has carried it on brilliantly.”
For years, England's camps were often portrayed as collections of rival club cliques rather than united squads.
Southgate, according to Sheepshanks, fundamentally altered that mentality.
“He was phenomenal how he drew England together to become like Club England, if you like.”
That approach came as no surprise to someone who worked closely alongside him.
Sheepshanks chaired the FA's advisory board, bringing together experts from elite sport, leadership and performance to support England's coaching staff in complete confidence.
Rather than second-guessing tactics, the group challenged managers to think differently.
“The idea is to expand the thinking and come at it from different angles in a completely safe, confidential way.”
One example has stayed with him.
“So the example I've used in the book was 2018 when we were going to Russia and it was Gareth's first World Cup campaign as manager.
“He really wanted to change the whole way in which England teams travelled, how they interacted locally, that they weren't seen to be arrogant and detached, but that they engaged with the local people and so forth.
“Gareth had a heading which was, 'How would I run the best possible training camp in Russia?'
“That was the subject.
“Everybody comes in and piles in with ideas.
“It's not that he doesn't have ideas himself, because they always do, but the idea is to expand the thinking.”
That willingness to learn, Sheepshanks believes, defines Southgate.
“He is a remarkable man.
“He buys into everything I was just talking about.
“He lives his life as a lifelong learner.
“He's curious and he wants to encourage others who work with him to be the same.”
Those qualities filtered directly through the squad.
“That was his players.
“He was phenomenal how he drew England together to become like Club England.”
Sheepshanks sees Southgate as the perfect example of the coaching pathway St George's Park was designed to create.
“The fact that he did run the under-21s...
“It was probably half by design and half by luck as it panned out.”
Southgate's route through England's development teams meant he understood the culture before taking the senior job.
His leadership style also reflected the educational philosophy Sheepshanks hoped would underpin St George's Park.
“Every day is a learning day.
“I'm going to go on learning until the day I drop.
“It does require a certain hunger to want to go on learning.”
That same mentality, he believes, was central to Southgate's success.
England ultimately fell just short of ending their long wait for a major trophy, losing successive European Championship finals before reaching another World Cup semi-final.
“I was mortified.
“I was there in Berlin when we lost in the final to Spain.
“We were only a goal away.”
Despite the disappointment, Sheepshanks remains convinced England's trajectory has fundamentally changed.
“I actually said way back that we were going to win by 2026.
“If you buy into the Kaizen thinking—incremental marginal gains, lifelong improvement—then by definition one day you're going to get there.
“And I believe passionately that we are going to get there.”
For Sheepshanks, Southgate's legacy was never simply about lifting a trophy.
It was about changing England from a collection of talented footballers into a genuine football culture.
And, in his eyes, that transformation has given whoever follows him the strongest foundation the national team has enjoyed for generations.