straw man

A doll or scarecrow, particularly one stuffed with straw.

(figuratively) An innocuous person or someone of nominal or lesser importance, as a front man or straw boss.

(figuratively) An insubstantial concept, idea, endeavor or argument, particularly one deliberately set up to be weakly supported, e.g. by misrepresenting an opponent's argument by broadening or narrowing the scope of a premise, so that it can be easily knocked down; especially to impugn the strength of any related or contrasted thing or idea.

(figuratively, engineering, business) An outline serving as an initial proposal for a project, usually refined iteratively.

Synonym of straw buyer