I have done it both ways, this last year I just disced it a couple times and planted and cultipacked. When you burn it down you'll get a better looking plot to the eyes but what I've seen is it doesn't matter to the deer what the plot looks like. Like Phil said you might have some clover in your brassicas but IMO it doesn't matter and it takes less time to do by just discing and palnting. Here's some pics of what I did last year. This is the cereal portion of the rotation so the fall of 13 I planted this and around the 4th of July I palnted my brassicas into this.
I clipped the rye a couple weeks before discing so it;s easier to disc.
I had a bunch of patial bags of different types of clover when I planted.
After hitting it a couple times with the disc.
Planted and cultipacked.
On the outside of this plot I have a 10-12' strip of clover
THis is what I had when the brassicas came up, some clover in there but they did good.
Around labor day I took a bout 8' and planted cereal grains back in there.
This was on 9/20 looking the other way from the previous pics
Hope this helps.