The real benefit to T&M is lack of tillage. This is especially important in poor soils like sandy or heavy clay. It takes years of mixing and rotating legumes and grasses to build the OM that was lost through tillage and is necessary for good nutrient cycling. Limited success is to be expected in the first few years. It is too tempting for many to backslide into tillage to get the short term gains at a long-term cost.
My general advice would be this. Forget about providing deer food. Focus on good soil building mixes and rotations. They will provide good deer food as a byproduct. T&M with little OM in sandy soil and trying to focus on deer is probably biting off too much. For example, the early turnips or radish followed by WR is a great technique when you soil can support it. Planting them together before a rain (rather than focusing on deer) and cultipacking would have served you better.
As soil improve, you can move your focus to deer first. As OM builds top down over time, and the sandy soil begins to retain more moisture, planting right before a rain becomes less critical than it is right now. I would forget crops like brassica when first starting. I'd focus on WR with an annual clover for starters in the fall. Spring might include something like sunn hemp and buckwheat. Adding a little GHR to the fall mix would give you some brassica component with organic tillage driving OM a little deeper, but I'd keep this component light. Notice that while the focus of this approach is soil health (do no harm with tillage and slowly build OM), this kind of crop mix will feed deer pretty well.
I too have done the two stage brassica and WR/CC planting. It worked much better after my soil started improving.
Thanks,
Jack