The part of the sentence "at a primitive stage" is correct and can be used in written English.
It is typically used to describe something that is in its earliest or most basic form. Example sentence: Scientists believe that life on Earth was at a primitive stage 3.8 billion years ago.
Such sophisticated campaigns are still rare in most parts of the world, and the internationalization of corporate philanthropy remains at a primitive stage in most countries.
"Ninety-nine percent of scientists probably don't believe pheromones exist in humans," said Dr. Murali Doraiswamy, a professor of psychiatry at Duke University Medical Center, though research "remains at a primitive stage".
Studies on rubric use or its impacts on ratings are steadily increasing, but are still at a primitive stage.
However, development of the molecular 'surgical instruments' to break and rejoin DNA strands at sequences of our choice and thus bring about desired genetic rearrangements is still at a primitive stage [1], [2].
Transmission electron microscopy showed that GSCs were at a primitive stage of differentiation with low autophagic activity.
Taken together, these ultrastructural features implied that the GSCs were at a primitive stage of differentiation with low autophagic activity (Fig. 5).
A lengthy primitive stage eventually led to commercial whaling; new markets and technical and chemical advances then produced modern whaling, which led to virtual extinction of the quarry and a return to a primitive stage.
In addition, the overall design process starts from a primitive stage and ends with functional parts.
So Orwell's own account of his motives is political — but it's politics at a very primitive stage, where it's pretty much the sum of his psychological impulses.
