Thanks very much Bill David Neil Searles Candon Catherine, so much information to try to digest. I've been trying to follow things through today, with mixed success, there seems a lot of supposition going around about how much archery there really was in the Late Bronze Age onwards, some say there is next to none, but there does seem to be general archaeology that shows that archery just took a major step backwards at some point, some say its the result of the 'hero' age of hand-to-hand combat, others that the power of mass infantry was discovered, but basically the picture is really confusing, not much evidence to go on and lots of big statements.
As for Ireland, there seems to have been some major population crisis going on in the so-called age of the 'Celts', with maybe only 100,000 people, so its likely the population is so sparse it didn't need to hunt but could be sufficient on agriculture. Whereas in mountainous areas like Pictland and Portugal the bow may have held more advantage in hunting. I'm not really sure of this, just an impression I have from today's reading.
The interesting thing though is that the Roman armies from earliest times did indeed have many units of archers, and they were usually auxiliaries drawn from the archers of various countries around, probably. So it would seem that archery was still widely available all over the place for the early and late Romans to draw upon (oh sorry dreadful pun ...) But this habit of hiring foreign archers as mercenaries and extras by the Romans, and then calling them 'sagittarii' may well explain why the 'sagitta' word for arrow then dispersed so widely. But if this is so, then the question still needs to be asked as to where the Latin word came from in the first place? If 'sagitta' isn't originally Latin, where did Latin get it from?
Another thing that I've read a few times today - again without any real evidence, but interesting nonetheless, and that is that archery may have suddenly become a kind of taboo, and could only be used in certain ritual contexts. Given that the Romans did actually have archery military units, I'm not sure that really holds up, but it might to some extent in that these units were foreign, so its just possible the Romans did this because they considered archery as 'contaminated' but useful. Its interesting that the old archer deities still maintain themselves in many cultures - and no doubt that is what we see on the Pictish stones too. But there is another idea that seems attached to archery/arrows in mythology, and that is the idea that certain gods use arrows/darts to cause plague and disease. And this may hold some clue as to why archery should be largely avoided, it may be believed that arrows are simply too risky in respect to bringing down disease on people. Its probably no coincidence that a Pictish archer deity is on a stone at St Vigeans, as Saint Fechin was reknowned above all for his 'hospitals'. But even if the arrow brings disease, it just pushes back the question as to why arrows would suddenly take on such a contrary mythology over so many cultures at the same time? Especially at a time when the science of bows and arrows was at its height. And strangely this one may be answerable, its because the archer constellation Sagittarius, which had probably always had dangerous and deadly aspects to it when it was the constellation of Samhain in the Neolithic, finally reaches the winter solstice - the most dangerous liminal point of the year. Bad double wammy so to speak ... But its also what happens to massed armies, they die in battle from arrows, then they die of disease from plague arrows. Then and now.