Some can, but the most organised Undivided, the Word Bearers don't usually deal with the fringe cults, since they view Chaos as a religion, it's like an organised religion dealing with cultists, heh. The second most organised Undivided one that abhors cults is Iron Warriors, but that's because of their battle doctrine. Alpha Legion and indeed especially Black Legion are complete opposite, usually taking advantage of every aspect of Chaos available.
Some Traitor legions are so close-knit in battle practice, such as Thousand Sons, that they don't either need or want cults, or even be able to use them. Not to mention, Emperor's Children, World Eaters, etc don't have an organised structure anymore but have formed bands of raiders and work as mercenaries of sort. Epi...Relic completely left this aspect out. Though, I'd imagine it had been sort of hard to implement in pre-Dark Crusade DoW and now they can't do an upheaval anymore.