I might agree with you, but I can't get around the killers taking the security cameras. Security cameras at KR and CR1's property. I don't care how experienced or professional the killers are, no stranger would have known where all those cameras were hid. Those cameras could have been installed years earlier. That area is so rural, no way any strangers could spend as much time as it would have taken to do the surveillance necessary to determine where all the cameras were without being noticed by family or neighbors. Then you have the dogs. 20 or so if iirc. Pit bulls, hunting dogs, and other assorted dogs. Dogs bark even when someone they know comes around. No way to get around that either.
As far as no evidence being left, there wouldn't be any DNA, fingerprints ect that would help LE determine the killer, if the killers were close friends or family members who had been in those homes numerous times prior to the murders. LE would expect their DNA, fingerprints ect to be there.
As far as knowing the schedules, activities, layouts of homes, a close family member would have known all that and more. It doesn't mean they were professional killers, just that they had been in the homes frequently and were up in the business of the family enough to know when they were home and when not.
I think the only one the killers were not sure about was DR, because she unexpectedly worked a double shift that night. The text messages between DR and AM took care of that. So as soon as they knew DR was home, JM called JW to tell him it was a go, that everyone was home and in bed.
None of this took an experienced and professional killer. It just took someone close enough to this family to know everything about them, including where the security cameras were installed.
It's long been my theory (and it was mentioned by some LE early on) that the killers may have had assistance from some acquaintance of the family. It would be too difficult for them to case all 4 locations and family members on their own without someone becoming suspicious. They could have gotten assistance from someone already familiar with the victims and homes, who could observe their daily routines without arousing suspicion. That easily could have been people concerned about the ongoing custody battle over Hanna Rhoden's daughter or someone else.