Adams' version of events is supported by the Tom Dillard pic, the Stroud document, the fact she never encountered Truly and Baker (and vice versa) and Baker's observation of two white men hanging around the area Adams said Shelley and Lovelady were and at the same time, roughly 60 seconds after the shooting.
She is a totally credible witness of impeccable character.
Just for argument's sake though...
Let's say you do have some intelligence and can manage this rudimentary thought experiment, you must agree that the only way for Shelley and Lovelady to reach the area near the freight elevators within 60 seconds is to enter the building through the front entrance moments after the shooting.
You must agree, as part of the thought experiment of course, that taking Adams' testimony at face value would disprove your identification of Shelley and Lovelady in Darnell.
Just for the sake of argument, let's say I have vastly more intelligence than you and see where that goes

...
Sure, I can agree to anything in the context of a thought experiment. If Shelley and Lovelady were on the TSBD steps when the shooting occurred and at the freight elevators seconds later, logic would dictate that they
were teleported by aliens - no, strike that, that they walked back there through the front entrance.
The value of a thought experiment hinges to a large extent on its plausibility. Otherwise, of what use is it? This was the problem with your LBJ-Byrd-Cason-Shelley-Dougherty thought experiment. When you acknowledged that it couldn't account for Oswald, I think most folks sensed the thought air going out of your thought balloon. Poof.
I will admit I haven't read
The Girl On the Stairs. However, is it correct that Vicki herself in that book disavows saying she saw Shelley and Lovelady and claiming that the relevant portion of her WC testimony doesn't even sound like her, as Roger Odisio states in this thread at the Ed Forum?
https://educationforum.ipbhost.com/topic/30023-vickie-adams-interview/. If that weren't sufficient, the thread opens by linking to a 1966 interview in which Vicki apparently claimed that she did see Shelley! Is Vicki's credibility hanging by a thread, or is that my imagination?
The plausibiity of your thought experiment also hinges on (1) Styles, who was there, either being flat wrong or lying for no apparent reason, and (2) the photo that clearly shows Shelley and Lovelady walking down the Elm Street extension not being Shelley and Lovelady, with fellow gung-ho CTer Bart Kamp having faked said photo for no apparent reason. All of this to prop up some elaborate conspiracy scenario that apparently requires two TSBD clucks like Shelley and Lovelady as well as the WC staff to be at least after-the-fact participants.
Pretty thin thought experiment gruel, it seems to me. Occam and I continue to prefer our version whereby Vicki actually does see Shelley and Lovelady a wee bit later than she recalled, which has the beauty of still allowing CTers to argue that the two cuties were teleported from the fourth floor by aliens and should have heard or encountered Oswald if he'd been coming down the stairs.