Oldfield habitat - Suggestions for guilds

Hello permies!

I am rethinking the design I made in my PDC in 2023. I had designed an orchard on an (what I now realize is an) oldfield habitat, in fairly straight lines serving as a wild break. The trees I was going to put in were a mix of fruit and nut trees, supported by Elaeagnus and other nitrogen fixing bushes.
I feel now that that idea was not really thought through, as for example chestnut trees prefer to be with other trees and not be stand alone in the middle of a field. I learned this through watching a documentary of a nut farm permaculture site in Skåne, where they have introduced many clusters of chestnuts with other species onto a new field.

So now I am thinking about possibilities of species that grow well on a oldfield setting. In Volume 2 of Edible Forest Gardens, they suggest shrubs that are running or thicket forming plants that then form nuclei. Then you could choose to at the same time grow trees in the middle of these scrub clusters or introduce them later into the forming nuclei? (I am assuming here.)

Our plot is in zone 6b, and has quite some southwestern wind.

I would love to hear anyone else's experience with starting food forest plantings in a oldfield setting!