Osmosis is one thing - but there has to be something to build on, and from.
It's' relationship, engagement, call it what you will Dogs and horses cannot possibly figure out what we want and train themselves.
Yes lots of what we build on is instinctive ( sports like barn hunt and herding are obvious - but the concept is much bigger - moving away from pressure, wanting to be with us are just two examples) but without a facilitator to explain the rules how on earth can the team work as a whole? They can't.
Period. Full Stop.
If you expect ribbons and glory - heck if you just expect specific behaviour it's YOUR job to invest time in making sure that behaviour is known, cue-able and fluent, Your JOB I tell ya. Hope you are listening!