No, you don't spawn two horses to get a donkey, you breed a donkey to a horse and get a mule.

Now, as to hatchery steelhead being genetically the same as wild steelhead, that's not quite true. It's like saying that a poodle is the same as a german shepard. Yes, both are dogs, but they have substantially different traits.

Hatchery fish were intentionally and unintentionally selected for a variety of traits over the years. These included the ability to survive without freaking out in hatchery tanks, early returning (which unintentionally bred the trait of racing through the river), and uniformity in size. We also bred a lot of the biters out of the gene pool, which is why in some of the rivers, such as the deschutes, the wild fish bite at three times the rate as hatchery fish.

So, while they are the same species, and are genetically similar, it's not accurate in my opinion to say that they are the same. They could be, if the hatcheries had that as a goal, but hatachery managers intentionally bred fish away from the wild phentotypes for 50 years, so it just ain't so anymore.