While other countries happily convert over to armies powered largely by arcanium, the multen continue to use bows. Countries like Matadoria and Hiboredia generally take this as further proof of how primitive the greenskins are, but the truth is that their land is poor in arcanium and they see using it to power weaponry as a waste.
The goblin bow (and related feats of engineering) is the result of the multens’ desire to stay relevant on the battlefield without the use of arcanium. Rather than simply being sized for goblins as the name implies, the goblin bow is perhaps the premier example of goblin engineering. It provides the range and accuracy of a longbow and the power of an arcanium rifle in a device small enough to be fired from goat-back or while concealed in a tree.
While many humans and elves consider their dependence on muscle power to be a failing of bows, the bulkier-on-average greenskins have an advantage on the punier sentients in this respect. Goblin bows merely multiply this edge; a giant with a giant-sized goblin bow can generally outrange a human with an arcanium rifle (though admittedly ballistics are quite a concern at that range) and is almost considered a siege engine in her own right by many human commanders.