Il-Cornfed is spot on.

Long term oats with good perenial clover like Durana would be great, but
it is too late to expect to get anything out of that now, or at least not the
clover. Long term, if pretty heavily shaded and small, you should get some
clover growing in there. But that would be for next year.

Brassicas will make this year, will be good after the first freeze.

TexasOaks, where I'm at (Louisiana) they don't hit the brassica's too hard until that first freeze somehow makes them more palatable, which can be very late (on into December sometimes). For a lot of northern hunters, this obviously isn't a big deal. I do have one small plot where they were hitting the brassicas this summer, so its not a rule that's set in stone. The deer will eat it, but I just don't think it is a preferred food until a freeze.