Another thought as I read your comments again. They say this virus is so bad because it gets into the lower lung, which they think is due to the small particles getting sucked in so deep.
The larger droplets may get stuck in the throat or upper lungs.
In reading about the standard flu they studied large and small particles, and thought that the smaller particles weren’t as viable as the larger, but it was difficult to determine. So perhaps this Covid-19 has more viable smaller particles for some reason. This would allow it to spread farther and infect easier (observed), and also to get deep into the lungs as observed.
To understand the question it helps to understand a little about the airway, how it functions. Your airway is much more than a pipe. As a molecule of air is inhaled it encounters 25 “forks in the road” before it finally gets to the alveoli, little sacks where gas exchange occurs. This has several implications. To get the air to flow through all these areas of high resistance it needs a little help because you may recall from physics resistance means more work, the “effort of breathing”. The air flow in the airway is “laminar flow” to reduce viscosity but this also does some filtering, l;Amina flow filtering. Each inhaled particle is progressively pushed to the side like a cohoe drifting in a river will eventually find the beach.