"stronger" (in the sense of "more damaging" / "able to harm in spite of armor") and "non-lethal" are two ideas that don't go very well together. You whack somebody with anything heavier than a police baton, and you're going to start seeing internal bleeding that can't be corrected with anything less than modern major surgeries. A stick is generally non-lethal - you really have to know what you're doing to completely kill somebody with even a smallish baseball bat, unless you are planning on beating them after they are disabled. A claw hammer, on the other hand, is going to break some bones and cause internal bleeding, and by the time you get enough damage to stop them from fighting, the wounds will not be very survivable.
Also, polearms and blunt ends are generally not a very good combo. The nunte was somewhat blunt either as a hook for catching prisoners, or because the people who built them could not afford blade steel, or a combination of the two. But it is a rather crude weapon originally improvised from farm tools on Okinawa. Not an easy thing to learn to use, and not terribly efficient as a weapon in general. Its real value is being a really cheap alternative to a good yari or naginata.
Seriously, there is little money in prisoners, compared to the value of the junk they carry (unless you're just picking off rabble that don't have anything). It's probably not worth your time to worry so much about capturing them alive, or if you feel a need to get a few alive, just run over them with a horse. The Japanese weren't too big on taking prisoners in battle - urban police forces were among the first to adopt policies on non-lethal force (hence carrying the jitte) for maintaining order, but organized bands of brigands were pretty much "wanted dead or alive, preferably dead".
