Trout and Salmon aren't proper clades. What you call the fish depends on where it lives, not what it's related to. In fact Rainbow Trout and Steelhead Salmon aren't merely closely related, they are literally the same species and will interbreed. Lake dwelling trout are the descendents of ocean-going ancestors that got stuck by dams and floods.
I'm aware - my point was exactly that - Atlantic salmon and brown trout are in the same genus, whereas pacific salmon and rainbow trout are in a different genus. Certain combinations of varieties of trout and salmon are more closely related to each other than other varieties of trout are to other varieties of trout.
