To be honest, at the time it was simply because the red clover was a bit cheaper. I think the deer prefer a white clover over a red, but I really don't plant the clover for the sake of the deer during hunting season. A late-summer clover planting doesn't result to much in the fall as they're mostly just establishing root structure. I mainly throw in clover because its a legume which, since legumes fix their own nitrogen, equates to free fertilizer in the plot. The deer and turkeys will work through the clover in the spring and summer, but there are so many other forms of browse available at that time of year I really don't put much stock in it. If I were doing a spring clover planting with the intention of providing a fall clover food source, I'd more than likely go with a white clover variety.
I tend to skimp on lime and fertilizer because I'm usually running low on play money during late summer. It's sad to say it, but I've never had a soil test done on this property and I've never limed either of the plots. If I'm planting a lot of brassicas I'll throw down some 46-0-0 urea at about 150-200# per acre. For everything else I'd say a 20-10-10 or triple-19 at about 200# per acre would suffice. For legumes like clover and beans you'd want to go with a low nitrogen fertilizer.
There's no doubt that if I'd spend a little more money and lime/fertilize these plots properly my end results would be much better. But for the money, I think my results have been pretty good... good enough at least. The nice thing about rye and oats is that they'll grow on damn near any soil. That's why when you look at the contents of the "throw and grow" blends, 90% or more of the seed is rye.