Is there room for small rotational grazing? I put a chick tractor over a patch then when its grown high, move it the next spot and let them graze it down. Don't feed them clippings, that will impact crops.
Otherwise, mine are doing well on foraging. I haven't even bought a seed mix in a week (accident) and their crops are still full. I do allow my little polish and 7 year old hen pellets, but they are special and need help. Amy (7 year old) is great at foraging, but the polish sucks at foraging, even with a bang cut.
I don't ever recommend polish except for pretty. Sucky layers. Flighty. Sucky foragers.