That is my best theory. It checks off every box for me.
I see absolutely no reason to discount the neighbors who said they heard 2 shots at 12:30 (the time was even corrected by the Sheriff, as the clock was a few minutes fast). I believe that these were the shots that took out James. I believe these shots were heard by the neighbors because they occurred while the suspect(s) was standing outside on the porch. From this point on, I believe the suspect(s) completely lost control of the victims. I believe Denise either fought back or ran and barricaded herself in a room of the house and Jayme was either in there with her, or she hid somewhere else. I think it took the perps awhile to get into that room, and once they did, Denise was killed. I suspect that it was Jayme who made the 911 call and she either dropped it or it got throw once they found her. I also believe Jayme was taken simply because the suspect(s) realized 911 had been called and because they are locals, they knew how quicky LE would respond. The didn't dare get caught firing another shot, so they had no option but to take Jayme and kill her elsewhere.
I believe the motive was robbery, but they lost control of the seen to such an extent that there was never time to ransack the house. And yep...I believe the suspects were probably hopped up on meth.
And that is all I have to say about that.