The phrase "as a formation" is correct and usable in written English.
It can be used when referring to a specific arrangement or structure of something, often in a military or organizational context.
Example: "The troops moved into position as a formation, ready for the upcoming drill."
Alternatives: "in a formation" or "as a structure".
As soon as a formation is established, one dancer moves out of it and links up with another group — a highly skillful display of evolving structural patterning.
As a formation whose main power consisted of its heavy infantry, the legion remained unmatched until the introduction of firearms and beyond.
Silvio Berlusconi, a center-right politician and media tycoon who was prime minister for less than a year in 1994, belittled the new Amato government as "a formation which speaks for itself, put in place with the sole purpose of keeping the left in power".
They lived in a crowded three-way relationship, so it all makes sense: the journalist Nancy Spain, Joan Werner Laurie, founder of She magazine, and Sheila Van Damm, who trained as a formation flying pilot, found there was no place for women in aviation, wondered what to do, and then became a racing driver.
Oswald Clint of Sanford Bernstein is hailing Russia's Bazhenov shale as a formation that will dwarf North Dakota's, and bloggers are noting that the state of California has enormous shale oil reserves of 24 billion barrels.
To improve effectiveness there is a trend to deploy multiple USVs as a formation fleet.
A typical abscess formation, such as a cavity formation could not be demonstrated, thus a MRI was performed.
The circular unit formation can be regarded as a homogeneous formation with a constant thickness and constant effective permeability.
A mile below us was a rock formation known as the Eau Claire Shale, and below that a formation known as the Mt. Simon Sandstone.
Appreciate soccer as a gestation -- a formation that may only deliver once but may produce the most beautiful moment.
Sinosauropteryx, as a Yixian Formation dinosaur, is a member of the Jehol Biota, the assemblage of organisms found in the Yixian Formation and overlying Jiufotang Formation.
