The way the silo works is it's sealed airtight, the weight of the grass on top compacts the grass below. The fermentation process quickly uses up the oxygen available inside the bin and since it's airtight it's less susceptible to secondary fermentation during storage. An experiment you can try is to put grass into a 200litre plastic drum, cut the top off 2 drums and put the grass in one and cut a slit part way up the side of the other and fit it over the one with the grass inside. Make sure to tape up the slit and round the joint with a few layers of bale tape as it still won't seal properly on it's own. Even loose and half filled the grass will come out in very good condition.
Where I grew up they didn't have fancy automatic silo elevators or huge tarps, you had a 5 meter by 4x4 shaft and your children and the neighbors children to distribute and stomp the grass as it came down.(after one was they covered it with a thick plastic tarp and filled it with water) So being all nostalgic it occured to me....I don' recall if we had a fan or not :)
digitalAngst It is the biggest milk farm in Norway. They don't need a self-propelled forage harvester because they only use it at home. If they start driving for others they would buy a bigger one.
Here in Krautland (right around the corner from my place, actually) there are some really small farms who are sharing a small Claas forager. I once had a talk with the head-honchos of these farms over a BBQ and a few bottles of beer about the economic value of self-propelleds on farms so small. MUCH higher throughput, MUCH better cutting quality, MUCH better working conditions for the driver, at about the same cost-per-ton compared to a drawn shredder. And they can be used in grass, maize, what-have-you. They even harvest young birch trees for biogas use in fall O_O tl;dr This 'big' farm should really research a little into the matter of self-propelled forage harvesters.