Times are changing,very few Aussie style saddles have a horn.
Most Australian stock saddles used to look like pic #2 however the American influence has them with skirts,fenders and oxbows now.
I also build roping saddles,team roping saddles ect but all on the American style.
The Aussie saddle was designed to ride in all day mustering or droving and usually has a strained web seat for comfort where as the western saddle usually has a solid ground seat which after about 4 hours feels like you are sitting on a concrete slab.
The western saddle is usually fitted with a horn used for hard and fast roping or dally roping..Not a popular practice here in Australia for working stock especially on bigger properties unless American orientated.