The owner/writer of that page called them 3 stage. (AMF,Jari, Lommbard and MotoMower Snow Shark) Doesn't mean they were sold as such. And while you are looking at that page, did you notice all the big old single stage blowers?? I remember those blowers being sold as "drift busters" and the "drift buster" was an option on some.
I remember a lot of those machines as new or relatively new.
On the other hand, Cub Cadet DOES build a 3 stage blower - gather, break up, and blow. See
Not sure why they call this one a 3 stage
Not like this one -
In investigating farther, it appears they WERER sold as 3 stage - at least the dynamark in the USA -