The phrase "a sort of junior" is correct and usable in written English.
It can be used to describe someone who holds a lower or less experienced position compared to others, often in a professional or academic context.
Example: "In the company, she is a sort of junior analyst, assisting the senior team members with their projects."
Alternatives: "a kind of novice" or "a type of apprentice".
Mollie Katzen's "Pretend Soup and Other Real Recipes"—a sort of junior "Moosewood Cookbook"—was popular among the Brooklyn thirtysomething set.
We were to share the apartment with a cook, a laundry maid and a sort of junior maid-in-training.
Instead, Maxcyte is trading on London's AIM market, a sort of junior market meant for small and venture-backed companies.
Of the major opposition parties, one, the Nationalist Action Party (MHP), has become a sort of junior partner to the ruling Justice and Development Party AKPP).
Since 1994, it has been a member of the interim Partnership for Peace, a sort of junior partnership in NATO that includes no military umbrella.
Still, some Oregon winemakers cannot resist the urge to make pinot gris into a sort of junior chardonnay by flavoring it overwhelmingly with oak.
Scalia dissented, stating that the issuance of the Guidelines was a lawmaking function that Congress could not delegate, and dubbed the Commission "a sort of junior-varsity Congress".
So as the UK declined in relative terms, becoming a sort of uneasy junior partner to the rising US despite being its ancestral Mother Country, and as the British Empire slowly inexorably became the Commonwealth, Fleming invented his secret agent.
Mr. DeMint, a sort of political godfather to the junior Republican representatives who engineered the health care fight and shutdown, said of his acolytes: "They represent the voices of a lot of Americans who really think it's time to draw a line in the sand to stop this reckless spending and the growth of the federal government".
McDermott's last novel, "Child of My Heart" (2002), was the sort of junior year abroad that artists sometimes take in mid-career.
