The Andean dark constellations are best understood as one object rather than five. Taken separately each is a resemblance and not a very strong one; taken together they are a sequence with a fixed order and a use, and the order carries the information.
The set as recorded runs Machacuay the serpent, Hanp'atu the toad, Yutu the tinamou, Yacana the llama with its offspring, and Atoq the fox, positioned consecutively along the Milky Way from roughly Scutum through to Crux and Centaurus. Their successive appearance above the horizon through the year tracks the wet season, the growing season and the herding cycle.
There is a further layer. The Milky Way itself is Mayu, the celestial river, and it is understood as continuous with the terrestrial water: it runs down at one end of the sky, passes under the earth, and comes back up. The dark animals are on the riverbank. The llama coming down at midnight to drink is not a separate story bolted on but the same picture continued.
The whole thing amounts to a hydrological and calendrical model expressed as animals on a river, in a place where water arrives seasonally and its arrival matters more than anything else. It is a very economical piece of engineering.