“A writer needs a pen, an artist needs a brush, but a filmmaker needs an army” is a saying that has been printed on many images. American actor and director Orson Welles (1915-1985) is credited, but it’s uncertain when he said it.
 
“A poet needs a pen and some paper to write his verses, while to produce a film you need very many things” was said by Russian poet and director Yevgeny Yevtushenko in 1984.
   
“A poet needs a pen, a painter needs a brush, and a film-maker needs an army” is an Orson Welles quote in the book Final Cut (1985) by Steven Bach. “He (Orson Welles—ed.) once lamented the filmmaker’s fate, noting, ‘The writer needs a pen, the artist a brush, but a director needs an army’” was printed in The Sun (Baltimore, MD) on October 11, 1985.
     
     
Wikipedia: Orson Welles
George Orson Welles (May 6, 1915 – October 10, 1985) was an American actor, director, writer and producer who is remembered for his innovative work in radio, theatre and film. He is considered one of the greatest film directors of all time.
       
Google Books
Armenia Today
Issues 81-86  
1984  
Pg. 23:
A poet needs a pen and some paper to write his verses, while to produce a film you need very many things. You are not alone making a film, lots of people help you to make it. Nobody interferes with the creative process of the writing man, while it is often on the contrary in cinema.
(Spoken by Yevgeny Yevtushenko.—ed.)
 
11 October 1985, The Sun (Baltimore, MD), “Welles: A Tragic Life” by Stephen Hunter, pg. 4B, col. 3:
He (Orson Welles—ed.) once lamented the filmmaker’s fate, noting, “The writer needs a pen, the artist a brush, but a director needs an army.” Only a few times in his career did Orson Welles have complete control of an Army, but it must be said that when he did, he made the most of it. In fact, he made art of it.
 
Google Books
Harvard Magazine
Volume 90
1987
Pg. 57:
“The writer needs a pen, the painter needs a brush, and the filmmaker needs an army,” goes the adage, and anyone involved with major productions knows that a host of individual creative talents all contribute to the final look, sound, and feel of a movie.
 
3 January 1987, Windsor (ON) Star, “Playbill” by John Laycock, pg. C1, col. 6:
YOU DON’T SAY—A cast of thousands: “A poet needs a pen, a painter needs a brush, and a film-maker needs an army.”—Orson Welles, quoted by Steven Bach in Final Cut. 
 
15 September 1989, Back Stage (New York, NY), “Point of View: ‘What I Really Want to Do Is Direct’” by Sidney Melsky, pg. 36, col. 1:
It was Orson Welles who said “A writer needs a pen, a painter needs a brush, and a director needs an army.”
   
Google Books
A Life in the Twentieth Century:
Innocent Beginnings, 1917-1950
By Arthur Meier Schlesinger
Boston, M:: Houghton Mifflin
2000
Pg. 154:
“To practice his art,” Orson Welles once said, “a poet needs a pen and a painter a brush. But a film-maker needs an army.”
 
Google Books
Conrad on Film
Edited by Gene M. Moore
New York, NY: Cambridge University Press
2006
Pg. 117:
Orson Welles once said that “a poet needs a pen, a painter a brush, and a filmmaker an army.”
 
Twitter
Orson Welles
@OrsonWelles
“A writer needs a pen, an artist needs a brush, but a filmmaker needs an army.”- O. Welles #OrsonsLastFilm needs YOU: http://bit.ly/tosotw
1:03 PM - 9 May 2015
   
Twitter
Cinephilia & Beyond
@LaFamiliaFilm
“A writer needs a pen, an artist needs a brush, but a filmmaker needs an army.”
Remembering the great Orson Welles on his 104th birth anniversary.
10:39 PM - 6 May 2019