One of the reasons the front came in so good was because you amended the soil, make sure you do that again. It makes a HUGE difference!
Get it from the same place and you should be good to go.
But that area will be much easier to do then the front, the water will actually sit and not just run off like a lot of it would on that slope.
Is that fescue planted now and a warm season dormant with all the brown spots?