You can always brine anything. It never hurts and often helps.
The big thing to remember with brine is to season it with the flavors you will be using in sauces or sides. This cohesiveness really brings a table together. For venison, I'd add crushed (whack em once or twice with the back of your knife) juniper berries, GARLIC, a bay leaf or two and some rosemary sprigs. I'd also substitute 16 oz of water with a DARK burgundy wine.
1 gallon of water
1 cup kosher salt
1/2 c sugar (or brown sugar or honey, depending on what I am making)
PLUS whatever seasonings I am using.
Obviously this doubles and triples well. Boil to dissolve, chill it.
I even freeze it so that I always have some on hand.
Depending on the thickness of roast, overnight brine in the fridge?
Post pics when you do it? I love deer season..