Well, I have a couple things I need to bring up.
One: Wellington never asked for longbowmen. It's more or less an urban legend, as I haven't yet come across an actual source or context for any such statement (or even such a quote). Wikipedia does state it, of course, but it cites Cornwell's
Harlequin (Grail Quest) as its source. Which is historical fiction: thus, I must dispute it (though honestly I'm too lazy to bring it up on wikipedia, so someone else should do it
).
That being said, by all means, let the British train longbowmen. I mean its not like there's any benefit to them
at all. It costs far more to produce a longbow then a musket, and
far more to produce arrows than bullets and gunpowder, in both money and time. Beyond sufficient sources of yew being found only in French-controlled areas, fletching, crafting, and fitting an arrow together is great fun, I suppose, but when pouring lead into moulds makes your bullets and gunpowder can be produced in large quantities, its completely inefficient and costly. Also, longbows have the tendency to wear out and break. Then there's also the physical constraints of using it, as for someone to be able to draw a longbow, they have to spend years, over a decade at least, to be able to fire it to the standards of your medieval Briton. Not only do you have to develop what borders on ridiculous upper-body strength to do it, but your bones will be deformed as a result of doing so. You're pulling a 150- to 200-pound draw weight here: you have to start training continuously and frequently from youth to be able to do that. So whereas one might be able to train and replace a soldier with a musket relatively quickly (say, a few weeks, or months at the most), longbowmen are irreplaceable, as they
will take a lifetime to train. Certainly, you could tone down the draw weight, but then its not a longbow, now is it? Moreover, doing so reduces both its range, lethality, etc.
It must also be noted that the fire rate and range of the longbow is greatly exaggerated by a number of posters. An exceptional (note the exceptional) longbowman in the Middle Ages could fire two arrows in three seconds. Does that mean he can fire forty arrows in a minute? Muscle fatigue greatly diminishes the rate of fire of a longbow as time goes on (not to mention things such as sickness, weariness, hunger, and attrition), and thus the quality and effectiveness of your longbowman will diminish as a campaign continues, faster then your musketeer, whom only needs to be able to raise a gun, load it, and fire. Already, the optimal sustained rate of fire for a longbow is comparable to musket rates of fire with the Prussian drill, and their effective range is actually far less than what is commonly stated, as their lethality goes down proportional to the distance (moreso than a bullet). Their effective range is thus much diminished.
Moreover, longbows are unwieldy. In close quarters, they're far too ineffective to use properly, whereas a gun can be used both as a spear and a club. This is also exacerbated in siege situations, wherein the cramped conditions makes firing a bow much more difficult than a gun (not to mention you can also take cover with a gun).
In addition to this, longbow trajectory is diagonal, and for its extreme ranges, has to rely partially on gravity. This trajectory actually makes the longbow more inaccurate than guns, which have a more horizontal trajectory, as people can simply move out of the way of the arrow volleys (not possible with a more horizontal trajectory); thus, the archer force has to anticipate and correctly assess their opponent's movements, else they're liable to miss entirely (see Marathon for an example of this).
Arrows are also less lethal than bullets. Also, given that we're on this subject, the longbow doesn't fit the same role of the musket. Longbow was an artillery weapon, fired in volleys, and as such, is actually comparable to cannon and artillery. Which, in this regards, they are outclassed heavily.
Moreover, by the time of the Renaissance, armor had already developed to the point where longbow arrows couldn't penetrate it. The only response to this is that one has to put more force behind the projectile. However, as I already noted, longbows pushed the limits of the human body already, and thus isn't possible to improve upon. Hence the world adopting crossbows and guns, with guns coming to the front due to cost, environmental aspects, etc.
The longbow was dropped for a reason.
So if the British did decide to use longbowmen units in the Revolutionary/Napoleonic Wars, well...
I expect them to be gutted by a cavalry or a bayonet charge, or blasted apart by either cannon or musket volleys; then, the British will cry about losing what amounts to a fortune in training and expenditure, and being unable to replace the units. Then the French win the war, as the British spent the large amounts of treasure necessary to subsidize coalitions against the French on longbowmen.
Of course no one ever made it to close range...
You're kidding, right? Because I can pull up half a dozen examples where they did without even thinking about it. Actually I can't think of a single battle involving longbows where the opposing force
didn't make it to close range. And, assuming the force that reaches the longbowmen still maintains the semblance of organization, they would almost certainly rout the longbowmen (due to the near complete lack of armor on the longbowmen), be they men-at-arms or cavalry.
Of course, of course. I merely meant, if the problem of inventing a generation that could actually use longbows was solved, couldn't Wellington of avoided the problem the member I was quoting of requiring protection. After all, an advantage of bows over muskets (And crossbows for that matter) is they can be fired in an arc, meaning more then the first two rows can fire, and over the heads of troops infront.
They still need to know where the opposing force is. You could fire a volley from the other side of a hill, sure, but you have no guarantee that a single arrow will hit their targets if you're firing blind (and if they're moving rapidly). They also have to remain within musket range, and most certainly within cannonading range, to fire and hit something. Also, mortars and howitzers.