Oh, Holly (real holly) is hard as all heck.... Like rhododendron and hornbeam. And carving it is a whole other skill... Japanese holly is a common foundation plant that grows dense and rather low. From a distance they resemble azaleas (but they have no flowers)
I tried Japanese Holly first since we have a “plentitude” and I could selectively lop and bend around pipe and hold with duct tape for several months to hold shape. We also have one large American Holly ladder needed to get what I needed. Still looks white and holds shape.
So, the problem might be solved like the Rockefeller center Christmas tree... Take some branches off .. drill holes in the trunk where it needs branching, and plug the holes by relocating the trimmed bits.
A solution probably better for HO and larger🤔🤔