Difficult to say about the Rack Master seed blend. I had high hopes, but left it on the garage floor far too long post-purchase. Got bugs in it waiting for some soil moisture over 10-weeks post purchase. Once broadcast, the deer, hogs, dove, Cardinals, squirrel, and turkeys wouldn't leave the seed alone and the soil moisture was too darn dry to germinate the seed they didn't eat. So it was a "failure" of sorts, and probably NOT due to the original seed.
When it quit raining enough to plow (in late September), it STOPPED raining for two months. Had I broadcast the seed in September, any germinating seed would have and did die out or became stunted from a lack of moisture.
Brassicas, turnips, beets, and most plants that require a good frost to start the conversion of plant starch to sugar (to become more palatable for deer) just do not perform well for me in this semi-tropical region. We don't get the frost. There is too great a "heat sink" off of Florida's Atlantic coast and the air/soil temp just doesn't get there.
I over seeded with a mix of Australian Winter Peas, Oats, Wheat, and Rye. The AWPs were eaten by the turkeys almost immediately. The Rye germinated well. The fields look great. Like a great big lawn! The deer can't stand the stuff. Too bitter I suppose. No frost. No sugar.
Lotta time, energy, labor, and money spent in an attempt to prepare wildlife food plots this year, and the end result is Blood, Sweat, and Tears. Go figure.