Planted 2 acres of them 2 years ago with brassicas. Small low to the ground plant, some viney ness, but no real mass.
Deer clipped them off with no results.
Neighbor farmer just did 10 acres of oats and peas ... lots of mass 2"-3" ... yes, the brassicas will out compete ... I would add red clover to your mix over peas. Will green up this fall and in the sprind. Over seed with WR in early september ...