Hello, i agree with those telling not to re-shred. Last year my neighbor was cleaning his land and offered me a about 20 m3 of cut down shrubs and bushes. We borrowed 13hp (Hecht 6389) shredder from my parents. Shredded half of what we had and burned the rest. It was more work, noise and fuel than we expected.
In my opinion household shredder works if you have spare money and need to shred occasional material after pruning or cutting down a tree or two, but not for big scale work. Have patience, cover pile up and let it decompose on its own is my advice.
Good luck
