Pure speculation alert here: let's suppose that Fd had an MO: let an accomplice, preference for an athletic female, do his dirty work so he doesn't get any DNA or fingerprints or fibers on to the body as he is obviously the primary suspect.
Female accomplice chooses a knife with which she is familiar. Unexpected amounts of blood. JFd fought hard because JFd is also athletic and knew something was coming by the May 22 visitation if not before. Fd was expecting JFd to run, as she had run before. But JFd knew about the GG theory Fd was enamored with - the premise being that GG was both mentally ill and cunning (IDK, I didn't watch the entire movie and skipped all descriptions of the plot as being stupid). On May 23rd, JFd decided to be brave for her children and stay and fight, to disprove the mentally ill theory to her children, even if it meant giving up her life. Truly a brave lady.
So much blood was lost in the garage. Pillows finally had to be used to smother. The clothes were cut off because a decision was made that the condition of the body could not support any type of suicide/lost in the forest due to misadventure type death as initially planned - the body had to disappear. To disappear a body, it is easier to dispose of it in smaller pieces. Rigor mortis will set in soon. An accomplice knows how to dress deer/gut fish/mountain type activities that a tomboy growing up in SA might know. Prep work was done in the garage on the mat of the Suburban. Ten rolls of paper towels were used and the ETA for MT with cap on driving the Suburban out (at 10:25 AM was very late considering the first appointment of 10:30 AM in NYC) was missed by an hour or more.
Meanwhile, Fd left through the mudroom door, forgetting to lock it, and biked back to the Suburban and it took 40 minutes for Fd to bike through the back woods. Jealous female accomplice, instead of leaving the cell in 69 Welles, or taking the entire purse, decides to read JFd's phone while waiting in the Suburban because she is that jealous. It time stamped the murderer's location. But heck, jealous female accomplice needed to know the answer to the most important question of the day: was it JFd who was still holding Fd's heart or someone else? All MOO.