A number of posters talk about sheep eating holly hay
, maybe goats too? I am persecuting the cedars (nasty gymnosporium infestation) and allowing the holly to fill in, so hopefully that will fill the shrub/evergreen/bird hangout niche. I would suggest honeyberry would get destroyed by goats, it is a shrub honeysuckle! If you have spaced your silvopasture to allow cool weather grass optimum summer growth with a deciduous overstory, then shrub options would be caragana and bicolor lespedeza for n-fixers. Also you could start some black locust
and protect it, then coppace it and stimulate suckering. Almost everywhere in the midwest has autumn olive as well and maybe redbud and mimosa which all tolerate a little more shade. I find the n-fixer shrubs are pretty easy here which is a pretty similar climate.
Biomass shrubs/small tree could be privet, coppace mulberry, whatever you see around that is looking happy. We had goats that ate catalpa like candy.
You are going to have a vine layer, so just assume the honeysuckle will be back and either the goats will eat it or you can introduce another species. I have some wisteria (in sequestered areas for now until I see how it behaves) which is also an n-fixer. Goats eat the heck out of it.
I'm kind of a Lawton fan, I overplant n-fixers and the other stuff will enjoy the goodies and fill in.