I'm not sure I fully understand the question, but if you are asking about baling behind a rotory versus a conventional, then I've seen some trouble with round bales when the straw is chewed up too much. The rotory type will break the straw considerably more. How many blanks are you running in the concaveIJ If you're running a small wire grain concave and all the wires are still in, you should'nt have to run many blanks with 4' of straw. The fewer blanks, the less grain makes it to the walkers.