Since no one had much else to say, I'll -try to add to the discussion.
My WGSL GSD had fuzzy soft fur as a pup all over. As he aged the black saddle on his back became a little longer and thicker- more coarse. The outer coat fur everywhere else also became longer. Not nearly as coarse as his saddle but definitely more coarse than the undercoat which always remained shorter in length but soft and downey.
When I say "coarse", I mean a thicker hair shaft, not prickly or anything.
When I brush him, it's very rare for any outercoat hairs to be in the brush. It's all about the undercoat.
Yeah, I probably mucked this up as well ;-)
Lynn & von Traveler