I think it is a fair comparison, and if Case continues to improve week to week he might well hold onto the job longer just like you pointed out with Warner. Definitely a correlation there in terms of the team wanting to start the veteran in order to win.
If he doesn't continue to improve, however, then we're going to see Goff much earlier. I'm still on the week five train, it makes sense to me UNLESS we see Case go into Arizona and win. So from that perspective this is a really important game. How Case plays this Sunday is going to factor in very much with that equation.