@Prowlers are the most common threat in @The Sundered Lands, ranging from an inconvenience to a death sentence based on their numbers.
They can be encountered traveling in:
Detachments counting below 6 - the most common encounter
Packs counting between 6-12 - not rare to encounter but not a daily occurence
Large Packs counting between 13-35 - a rare occurence, Large Packs are usually a death sentence to lone travelers and a major threat to smaller settlements
Hordes counting between 35-100 - usually a once in a lifetime encounter, considering there is no hope surviving a head on fight. Hordes are a death sentence for smaller settlements.
Legions counting above 100 - not encounterable outside of @Ashen wastes they are a minor threat to the @Grand Bastion despite their overwhelming numbers. Only Ashen Vanguard expeditions have fought and survived encounters with Legions of prowlers, since they have units dedicated to scattering and destroying such conglomerations.
While Detachments and Packs can be taken in head on fight, Large Packs and Hordes have to be lured to chokepoints or thinned out with explosives first. Sometimes experienced parties of warriors with demolitionists can take Hordes head on and live to tell the tale.
Legions cannot be scattered or destroyed and have to be escaped instead of fought.