I don't believe you wrote a rant. I thought it quite a good posting demonstrating a lot of common sense. However, I also believe we're using a sledge hammer to kill an ant.
Canister from whatever nation had the same purpose-to kill enemy troops in large numbers. It was an anti-personnel round (and still is). It's a very simple round and generally acts the same when fired whether or not it has an iron base, a wooden base, or whatever else is attached. It was made of sheet tin during the Napoleonic period, which could be expected to rupture in the gun tube by the force of the explosion of the powder charge. Most, if not all, of the references state that the cone of the balls begins at the muzzle and continues to widen down range until the kinetic energy of the munitions is expended. It's quite simple, really.
Both the British and French used tiered canister. That makes sense to layer or stack the balls in the canister for firing. It makes the round more efficient. Both DeScheel and Tousard talk about this. They also give the dimensions of the target fired at and how many balls of both types of canister (large and small) hit at maximum range, and note what would happen to the target at close range-the target would be destroyed. Col Elting was talking about French canister rounds. He also noted, which agrees with some of the other contributors, that large canister was sometimes referred to as 'grapeshot' even though it was in a canister and not the usual makeup of a grapeshot round.