Renegade Marauder Squad
Renegade Marauders are troops of the Lost and the Damned. Consisting of Pirates, mercenaries, and other raiders abound in sectors that have fallen to Chaos and rejected the Imperial Cult, many renegade leaders are willing to pay exorbitant fees to coerce these masterless rogues into their forces. They are considered as the 'elites' of the renegades and are much more skilled in combat than your average Cultist.
Tabletop
7ed:
The base points of a Marauder Squad is relatively decent, considering they have WS4 I4 A2 for base staats, and the leader comes with a second wound, but to add more models to the squad, you’re paying 10 points per model, and if you want to add up to 2 Brutes (stats of an Ork Nob with +1W and Rending), you’re talking a whopping 30 points per model. As they’re “In it For the Money” the unit is unable to regroup for any reason after failing a morale test, which means once they fail a LD8 test, they’re effectively gone from the game. The upside is that they get one of 3 special traits for free, either Stalkers (outflank, stealth, move through cover), Murder Cultists (furious charge and crusader), or Hereteks (4+ armour save and krak grenades).
The only way you could make this unit work is by keeping them cheap, taking 2 meltaguns and having them outflank in a Chimera or Arvus.
8ed update:
These guys are how Chaos get Sniper weapons in play to stop Commissars from babysitting Conscript blobs. If the Loyalists and Aeldari in your metagame aren't bringing Scouts or Rangers, you might just need to put some scopes on some Cultist's Autoguns and get your hands dirty.
So, 34pts gets you five guys with two Sniper Rifles that hit on 3+, who'll generally be harder to shoot out of cover than Chaos Space Marines due to enemies being at -1 to hit - and usually require your opponent to wipe them out to neutralise their threat.
Sadly, their points-to-power conversion is extremely inefficient, probably on account of being costed up on the assumption they've got a power first, plasma pistol, and two melta guns. Which, to be fair, may well be a handy loadout for a dedicated Renegades & Heretics list.