If we (the royal we) know that someone's child being tortured is better leverage than torturing a grown man himself, it's reasonable to conclude DW knew that, too.
Just curious as to why you assume he couldn't have thought of any of this on his own?
I haven't been mentored in crime, I don't have any relatives or friends who are criminals, I haven't taken any courses in criminal mentality or psychology, forensics, law enforcement or crime scene cleanup and yet I can figure out how to do lots of things without help. And yes, I have learned a lot from watching TV, movies, news reports, interviews, reading books and articles. If I can learn what to do while committing a crime, DW can, too. Perhaps you qualify for Mensa; I don't but I'm at least intelligent enough to know fact from fiction when I watch TV, belch and scratch my belly... nyuk nyuk nyuk.
It has been reported he wore gloves. Lots of burglars wear gloves. He used items at hand to bind and kill his victims. He didn't bring a murder kit that we know of.
I doubt LE underestimates any criminal's intelligence, that would be a mistake. LOL, autocorrect keeps trying to tell me it's incorrect to write "criminal's intelligence"!
I'm not alone in my opinion that this was only meant to be a daytime burglary of an empty home and it turned into an unplanned and sloppy kidnapping, torture and murder.
I'm not sure what to make of "someone in the truck" giving instructions and cash for laundering to those women. A partner in crime for the planning but who wasn't at the murder scene possibly? I don't know. Maybe he was the brains, maybe he was half the brains. Phone records will show a lot.