So you’ve never heard of Kremlinology. As a retired intelligence officer I can tell you that parade composition is indeed used as a data point in intelligence gathering. What equipment is used, how much, who attends, where the bigwigs sit relative to each other, how healthy they look or don’t look, etc. is all analysed and can reveal a lot about what is going on politically and militarily.
Russians probably limit the usefulness of “Kremlinology”, particularly during wartime. Russians may even try to use “Kremlinology” to general false information.