Yeah, I don't think they planned it ahead of time, either. Too many stupid moves on their part to support that theory, imo.
Bissey says they DID arrive together. He said he saw them drive up, one of the players came out to greet the women as they got out, and then all went to the side door.
I have wondered if Mangum got in Kim's car for a minute or two before they went in. Maybe the car with Mangum drove up, Mangum got out and then got in Kim's car for a minute, and then they got out, and Bissey simply conflated the two events into one.
The defense needs to investigate both women's movements for the entire evening prior to the party.
The defense has maintained in their timeline that the two strippers came separately, about 30 minutes apart, Crystal coming around 12am. If Bissey is correct, then the defense would have to be wrong, and the timeline pushed back to when Kim arrived. That helps the prosecution, not the defense, since it makes out the players to be liars, given that Bissey is saying that a player met both strippers out front when they arrived in the same car.