Hey! I think inoculants can be useful to help spread biology from one place to another. Especially anaerobic ones like yeast witch can not transport via spores in the air.

I think in nature animals are always inoculation their environment with dung, saliva etc.

So sugars would essentially help to wake up sleeping biology, but inoculants themselves would more spread the biology from one place to another.

You can inoculate you soil with local microbes found in untouched forests for example . Nigel Palmer wrote an interesting book on that topic.

He essentially uses the top layer of the forest litter for biological amendments.

Another thing to keep in mind is that if you use inoculants they need an environment where they can live in. If you use them on highly compacted soils I would decompacte first and inoculate after.