Sorry for not explaining the motivations better. The tubes and the nail weights serve two different purposes. The nail weights help balance the bait, compensating for the lead drilled out of the bottom of the head. The tubes are just a more robust way of attaching the body to the head. It would be possible to prorig the bait without removing the body or the bill, but both are going to tear off after a handful of fish (which is why they have to sell that special glue) and I figure as long as you're going to put it under the knife you might as well improve the bait in other areas.