You are correcto The whole sponsorship process is quite extensive and requires a lot of patience from the Employer and employee.
To make it easier to qualify for a sponsored workpermit you need to skils that no American does not have.
Fortunately for all you Wannabes hoping to fly in the US pilot reqruitment is speeding up all the time.
Major airlines not to mention the Commuters are lowering their hour requirments all the time, thus leaving the entry level airline jobs such as small parcel flyers ( Ie Ameriflight and Air Net) desperate for pilots.
If you are a US citizen or a Greencard holder why would you even bother to fly for some of the smaller pt135 outfits when you can get in to the airlines ( Majors ) with about a 1000 Total and 100 multi.
Hope this answered some of your questions.
JJ