Keep in mind, we live in a desert here. but we have pivot irrigation on every acre of corn. Proven fact about "here": you can cover up lots of mistakes with pivot water. 

In regards to soil finisher timing, I have noticed the last few years that our best stands by far, will be in stable and settled ground. NOT just behind our soil finisher. We run a Deere 2310 Mulch finisher. Most of our acres are corn on corn. We lightly disk behind combine, then coulter chisel in November. This year, we are going to finish plow the majority of our acres 14-21 days ahead of the planter. Then we will spray with a pre emerge herbicide, followed by .75" of pivot water to settle the ground back down and incorporate the herbicide. The few places we have done this, even if its just 3-4 days early and .30" rain, the trash seems to flow better around trash whippers (Martin floating), less trash pinning in seed bed and the planter seems to ride smoother. Another example of this is our strip till. If we have a low trash, danger of blowing environment, we will strip till in March, then plant in April. That settled ground consistently has better stands. Yet another example of my "settled ground theory" is our corn behind potatoes. We will Paratill the cover crop wheat in March, water the soil to settle the ground back down, spray the wheat to kill it, then no till plant into that wheat. Stand and yield are always good.

One last thing we have noticed about our finish plow, the lower the angle of A-B line vs planter line, the better ride quality of the row units (based on planter monitor ride quality). Example: plant on 0 degrees, Finish plow 359 degrees now. We used to plow 340, that was noticeably rougher. Even 355 was noticeable. We used to plow the edges off last. Planting across those end rows would show up really bad on ride quality, so now we plow the edges first, then plow our straight passes (here, we are able to turn outside the edge of our fields)  Just my humble observations on our farm.