I know Jon Lieberman is one of NG & JVM's "talking heads" but based on my personal knowledge/experience of him professionally and adding his AMW credits I wouldn't be so quick to discredit his reporting simply by the company he keeps on occasion. If he went on live television and stated his police sources told him something directly I'd tend to believe him. JMO, of course... I don't expect everyone to buy into it.
If you add Jon's statements last week from his police sources; not the primary crime scene, "eyeball identification very, very quickly" at the scene, bodies had not been there for 4 or 5 months, etc.... to the use of "bodies" vs. "remains" in every news report and quote from MSM including HC & LE.... the short amount of time LE spent at the scene (only two & half days)... and that the ground did not look disturbed except for grass being cut & a few tree trimmings (no sifting of dirt, digging, etc.)... Adding all of that together I think it is relatively easy to formulate a solid theory that the girl's bodies were placed there recently... which is HUGE.
As far as the clothing that was found with the girls - they may not have been wearing it. The killer(s) could have left that evidence there along with the girl's bodies. They may have been wearing entirely different clothing when they were found or none at all. Maybe the girls had been kept in a freezer in the clothing they were wearing.
Determining time frame of when they were killed will help identify possible locations of where they may have been for the past 4-5 months (alive or preserved) and then leading to who their murder may be.