I've never towed and even I know that with towing its best to get as much weight on the axle of the trailer than to do that.
Actually tongue weight is good. If your tongue weight is too little the trailer behaves badly (ever seen a trailer that's squirrely for no good reason?). That said I don't know the factory tongue weight rating on a ZJ. On an XJ that rating is all of 500 pounds. So in an XJ you'd want to set that weight up so that the tongue has nearly 500 pounds on it (in load plus trailer weight). That would probably mean that load is mostly over the trailer axle(s), maybe biased forward a little bit.
Very nice! Real good for prairie dogs and rats if you go over to the east side at all.