English Etymology Random House Webster's Unabridged Dictionary, 1986 passim, shows first known usages for things insubstantial date to 1585-95. Universal Dictionary of the English Language, 1897, Vol 4, p. 4485, notes "man of straw" as "The figure of a man formed of an old suit of clothes stuffed with straw; hence, the mere resemblance of a man; one of no substance or means; an imaginary person."
Noun straw man
Translations trans-top|doll or scarecrow German: Strohpuppe f trans-mid trans-bottom
trans-top|insubstantial concept, idea, or endeavor trans-mid trans-bottom
trans-top|something deliberately set up weakly supported trans-mid trans-bottom
trans-top|front man or straw boss German: Strohmann m trans-mid trans-bottom