Sanchez is a #6 overall pick in his fourth year -- they didn't bring Tebow in to replace him. (Although, if you think they did, I can see some evidence for that).
But I was really using those words to apply to the other scenarios, like Brady. My point was that I thought a team with an established starter would pick him later in the draft, to use him in situations while fulfilling a backup role and developing.
The Jets situation is closer to that, even if Sanchez's mediocrity makes it a little more shaky. The point is, the clock is not ticking on starting Tebow. It has a different feel.