MOO
I think perspective is important. It's easy to get distracted by a theory, SM posts or watching videos, and get drawn in by the specificity. In the narrow perspective things may look logical and/or acceptable. However, there is a big picture and, in my opinion, it is best to keep it clearly in mind. It is also best to remember Occam's razor (see below).
CW CONFESSED to killing SW, which would include the unborn baby. Two killings (murders?)! By his own admission; HE IS A KILLER, and by his own admission; HE TOOK NO OTHER ACTION!
CW has given no indication that he tried to resuscitate, or help the girls in any way!
CW then had the opportunity to call for help. He did not call for help!
Instead;
CW took the bodies over forty miles away (an hour trip?) to a remote location. He placed the girls bodies in tanks of oil. Each in a separate tank. The most logical reason for this is to mask the small of decomposition and to destroy evidence. The most logical explanation for separate tanks is to avoid a volume disruption/increase that might be noticed by sensors. The most logical explanation for the girl's being wrapped in their blankets is to make handling them easier and to hide them while they are in the truck and being moved.
CW buried SW in a shallow grave at the same location. The most logical explanation is that the grave was temporary and he planned to return and move the body.
CW went to work without notifying anyone of what happened and made calls and texts to SW's phone to make it look as if she were still alive.
CW had the opportunity with NAU and LE to tell the truth. He lied! He lied repeatedly. He misled LE obstructing the investigation.
CW gave interviews, where and when, he repeatedly perpetuated the idea that SW, Cece, and Bella were still alive and missing. His behavior was odd, at best, and contrary to that of a concerned and/or grieving parent/spouse. At times he was happy, perhaps even gleeful.
CW's behavior was so odd when he stayed with friends, that they immediately contacted LE when he left.
CW had the opportunity to tell the truth to LE and help with finding the bodies, instead he delayed and bargained.
CW, after being caught in more lies, ADMITTED he was having an affair with a co-worker. He has admitted being an adulterer!
SM and Videos give a narrow and limited view and are open to interpretation. CW's words and actions are obvious and clear.
"Occam's razor (or Ockham's razor) is a principle from philosophy. Suppose there exist two explanations for an occurrence. In this case the simpler one is usually better. Another way of saying it is that the more assumptions you have to make, the more unlikely an explanation" - Wikipedia