Thing about goats, breeds that are hardy in one region might not be so hardy in another. Also, some breeds are better escape artists than others. Older goats in my limited experience tend to eat more of the branches, whereas younger goats tend to focus on the leaves. I haven't seen a goat yet that does not love rose bushes. Also, for brush and small trees, it is better if they have well developed horns like in the pic below, so they can break off branches and tear up bark. Notice the chips in the sharp edge between his horns, that is from trying to break things with his horns.
If it is just for brush and not for meat or milk, then I'd recommend a spanish goat. Since they ran wild in North America for centuries, they are acclimated to this environment and hardier here. The disadvantage of Spanish goats is that they are excellent jumpers. 4-5 strands of barbed wire like some cattle pastures have will not hold them. My Spanish buck can clear a 4-5 foot fence with no problem. If he was feeling lazy, he would jump in between the strands of barbed wire I had above the field fencing. Now I have two layers of field fencing that brings it to nearly 6' tall, and it is containing him so far. However when I have some brush or poison ivy to clear, he and what i suspect is his daughter are my go-to goats. I stick a leash on them, try to tie them where they are less likely to get tangled, and periodically go out to untangle them since some goats will find a way to get tangled on a leash when it doesn't even seem possible. (I would not recommend leaving a goat on a leash permanently, that is one way to get them killed.)
Here is an example of his work, I think it is a pear tree but it won't bear fruit this year. He will stand up on trees, bend the branches so he can reach them, and he will use his horns to debark and snap branches. (Also notice that it is outside of his pasture but he still managed to get at it.)
Fainting goats are also hardy for this region since they were developed in Tennessee about two centuries ago, and they are smaller so I've heard that they aren't as good at jumping out of pastures. However, they do collapse when started, which might not be a good thing with cattle and large pastures.
Boer goats tend to be easier to contain with typical field fence, although there are exceptions. I have one Boer that will climb any fence I have except for the 6' fence so far. I have another boer that is terrified of leaving the pasture, and will try to get back in when I let her out. They are beautiful goats and popular for meat, but here in my area of the Ozarks they haven't been very hardy (too wet).
The Nubians I have won't try to escape unless they are following the herd. One seems very hardy, another isn't so hardy.
I've had mixed results with Kiko mixes. Both were very sweet goats and easy to get attached to, they were friendly and had lots of personality. The one with LaMancha ears was very sweet (except to dogs and any female goat that tried to boss her around, she was the only goat that my guard dog was scared of). I don't know what one died of, the other died of her and my stupidity. She would only stay in the pastures at night, during the day she would climb or jump her way out. So I leashed her, and she got her leash tangled in her own legs next to a pond and fell in.
There are other breeds, but I'm not familiar with them.