I would argue that Metropolis is mostly follows the idea of Myth as a strategy and technique. Constructed in 1927, after the first world war and the middle of the Weimar republic it uses the machine cult aesthetic of his time and place that becomes vehemently anti war, and suspicious of how is consuming and who is literally being consumed.

This can be found in several places. He literally calls the machine that eats the workers Moloch (screencap of Moloch Image), another word for Ba'al, who was what ancient Jews called a Hittite God that was fed babies. This image of Moloch was used frequently by socialists in Europe from the 1900s onward, for example this 1901 issue of the socialist journal The Daily People (Link). It was later used by Ginsberg in the second part of Howl. Ginsberg's parents were Russian Jews, who were familiar with this kind of language, as he hinted in Kaddish.

Moloch is the most literal of the signifier that suggest that Lang's creation “goes into the world and maintains, legitimates certain social structures, and dismisses others” (From the lecture notes). He follows the woman he saw into the underworld against his father's advice, and he negotiates with the woman Maria. It sounds like the beginning of a Campbellite monomyth, a sort of Deco Eurydice and Orpheus. But that she seeks to wait for labour mediators, for the liberation of her (seemingly) permenat withering away of the state suggests that Lang viewed this as a reconstruction of that myth for ideological means. This was noted by the critic Axel Eggelbert in 1928, when he called t he film “an unshakeable dialectic of the class struggle” (quoted by Andreas Hellesson in The Vamp and The Machine, Technology, Sexuality in Fritz Lang's Metropolis (link)

Hellesson's use of sexuality indicates in general how myths of heterosexual romance are co-opted by a system of narrative ideology that “makes certain things true and certain things false. “ (lecture notes) The leader of the upper classes Federson's chief rival for the affections of Feder's mother, who created a robot that looks like her. This robot recasts the primal scene as a Promethean narrative,(screencap) or in other words a mechanical simulacrum of flesh. In this way even sexuality itself is sublimated by the machine. This fear of mechanical reproduction suggests that Lang is using mythology already founded to push an anti technocratic agenda.

From that point on the myth is used to recreate Lang's idea that the machine, and industry, make flesh indistinguishable from flesh, and it corrupts both of them. For example, the robot goes on to dance erotically in a night club; Maria is caught and imprisoned by Federson's heavies and then is basically raped. The robot's dance causes a riot and the sensuous dancing of Maria extends this idea that the flesh of a woman or the flesh of a machine work in conjunction to force workers into a fury. (the idea of a woman sexually exciting workers to riot seems more palatable, more politically acceptable then the workers rising due to more economic conditions, though the results are the same) . That the robot ends up pushing the workers into even greater levels of frenzy, into erotic excess and as a result the workers break down, furthers the idea that Lang is using this text as a way of making flesh flesh, of being worried about what this new industrialism would do to common workers.

The central thrust of Helleson's article points out the difficulty of this crafting of ideology use function into classical myth or biblical myth (the already mentioned Promethean and Eurydice references, but also belly dancing scene that reminds one of Orientalist visions of Jezebel, the Edenic garden scenes of the upper classes before we are introduced to Maria, and that Federson's temple is called New Tower of Babel) Helleson continues: “The imagery of the tower of Babel relates to the technology to myth and legend end The biblical myth is used to construct the ideological message about the division of the labour into the hands that build and the brains that plan and conceive...(ibid, 35). This sense makes eternal, iconic, and formal problems that are about daily life, democratic, and often lack a visual focus.

Lang does not “assume that myths are self evident” and he does use them as a technique or strategy which enacts his own agency, but he does not realise that how he uses these myths for his own purpose can have a problematic history past what the author intended. Myth has a habit of being a bogey man, not easily killed and popping out where it might not belong. In this case, the film is worried about women, (cf Helleson's discussion of technology bringing creation with out the presence of women, ibid 234) paradoxically, and uses two of the central myths about the concerns about women, that they will be created without the presence of men, and that they cannot be controlled when men love them, into a text that allows for the destabilizing power of female flesh, but reinforces traditional attitudes around them. In this way. Lang as the amalgamation and producer of this myth, allows the Weimar lust for and fear of the machine to be imprinted into an already presence fear of women's autonomy. The ideology then becomes fascinatingly accidental.