Here are some things I took into consideration as I started planting hedgerows to form windbreaks and (hopefully) living fences for my sheep:
1: Chosen species must be hardy and adapted to local growing conditions.
2: They must be relatively fast growing.
3: They must form a dense branch structure close to the ground (Shetland sheep can be escape artists).
4: They must be able to tolerate sheep browsing on leaves and twigs (Shetlans also think they're goats and love to nibble brushy stuff and tree leaves).
5: They must be cheap/free to source as seedlings/small whips.
6: They must either naturally form multiple trunks or sucker easily in case I need to cut them back to produce a thicker stand.
7: Preference for species that produce blooms and fruit.
Taking all of that into consideration, most of what I've put into my hedgerows have been tree seedlings that have shown up in their own in my planting beds: crabapples, honey locust, mulberry, red osier/dogwood, and hawthorn. I've also got a few hardwood (mostly oak and maple, with a couple of osage orange and buckeyes) whips I've planted in for larger shade trees, and a few non-natives (russian/autumn olive, nanking cherry). And I've let things like black raspberries grow up and around the seedlings as they've gotten 3' or taller. I'm only a few years into the process, so I have a long way to go before the hedge is tight enough to contain the sheep, but it already provides some benefits to wildlife (food. cover). and I keep adding to it (length and width both--ultimately I plan for a 4' max width, especially where I need a windbreak) as I find more seedlings in places where they shouldn't be.
Bottom line, a hedge has to meet the needs of YOUR property, so look at what grows well in your microclimate and meets your needs for food/fodder/flowers/habitat.