That time the hunting bow was the weapon in the war.
While probably correct this statement is only an assumption and should not be stated as fact, we do not have sufficient data to draw any such conclusion, we do have data that shows that some groups of people, admittedly from different areas of the globe, did use different bows for war. The fact none have been found is not absolute proof of their absence it is only an indicator.
"Whitout armour they doesn't need the heavy warbows as Nidrinr mentioned."
Again another assumption, heavy bows are not only used for war, what weight bow would you choose to use against an Auroch, standing 2m at the shoulders, weighing over a tonne, and with the disposition of a cut snake? Ötzi's bow, even if it is accepted as being unfinished, was not exactly a light "hunting bow".
What weight bow was used to hunt with in Medieval Britain? again we don't know, we have books written fro the gentry advocating "light bows that can be held at half draw", now if you can pull a bow you can hold it at half draw relatively easily, so these books are nonsense and are for the gentry anyway. We do have anecdotal evidence in the form of both paintings, prose and arrow heads, that suggest the hunting bow was heavy, Look at some of the paintings contemporary to the times the bows appear to be heavy, Geoffry Chaucer wrote "The Canterbury Tales" sometime between 1387 and 1400, and in it he has a character called the Yeoman who was a "proper forester" that is a person responsible for looking after the forest, enforcing forest law and hunting or arranging hunts for his lord, according to the prose this "hunter" bore a mighty bow, not a light bow but a mighty bow. You also only have to look at the swallow tail broadhead which wasit is believe is only intended for hunting deer and you will see that it could not be used in a light bow.
Craig