Nope.

What you propose is such a significant shift from what we have now, why have any payrate separation at all? Everything pays the same.

In effect that is what you propose except there are 2 tiers in your example. If you can defend 2 tiers, you can defend 1 tier/ no tiers. If you think there should be 2 tiers, then you should also think there should be 6 different payrates.

As I see it, there is no difference in payrates or there is.