"vast assortment" is correct and usable in written English.
You can use it when referring to a variety of items. For example, "The store offers a vast assortment of products."
The novice gardener may be overwhelmed by the vast assortment of fertilizers that fill the garden suppliers' shelves.
From China, a vast assortment of cheap consumer goods for local markets comes down the road, particularly to Lashio.
The spacious bakery cafe is outfitted with cases filled with a vast assortment of cakes, cookies, pies and chocolates.
In between are about 75 films from 15 countries, a vast assortment of work in practically every conceivable format, from Hollywood features to home movies.
During seven visits to New York, she captured on film a vast assortment of breeds and mutts, purebreds and rescue dogs, and presents them in vivid color.
He shared a life filled with brilliance and insight and courage, a vast assortment of fascinating and talented people, and sheer celebrity.
Prepare your vast assortments of rocks in a small or compact pile.
Scrambling a vast and witty assortment of visual and aural references, "Maria del Bosco" translates the siren call of glossy materialism into the splintered terms of Mr. Foreman's shifting dreamscape.
As they search for better returns, more investors are discovering that the road to riches could lie in the vast global infrastructure: an assortment of companies that build or manage highways and tunnels, water and waste systems, parking garages, airports and other properties.
Coral reefs are among the most biodiverse places on earth and provide a habitat for a rich assortment of fish including a vast array of predators, which can account for up to 50% of biomass in some reef communities [28].
The designer Caitlin Mociun has filled the vast space, once the home of a furniture company, with an assortment of her hand-drawn print dresses, neon swimwear and delicate jewels.
