You're allowed to NPC them yourself if you so wish! Anything crazy (single-handedly attempting to track down and assassinate Albero himself, for instance, or blowing up mafia bases or IDEK) should be run by me first, but murderising a few of the wandering gangs should be fine.

As for their battle-readiness, it varies. They are equipped with guns, generally, with the night-time gangs carrying harder-hitting and more expensive ones. The gangs no longer necessarily contain a fully-human leader - some do, but most teams are now comprised solely of animal-spliced members, which come in several types:

Dog-people - tend to be used as trackers and feature heavily in groups that actively hunt the Numbered. A little more durable than the average human,but nothing spectacular. Typically look fairly ordinary, but can be identified by long tongues, canine teeth and a great line in puppydog eyes.

Cat-people - actually based on big cats, mainly jaguars. The same type that have been used a lot by Albero before - they're very fast and stronger than normal humans and come complete with night vision.

Bear-people - tanks. Extremely durable, tend to favour beating victims to a pulp over using firearms. Also tend to have bear claws and excessive body hair.

Snake-people - less common than any of the above, tend to hang back during fights and only move in to attack a downed victim. They have forked tongues and fangs that inject poisonous venom. NASTY AS HELL.