I don't believe the blitz attack theory is feasible.
Though I think the SR and PW duo is probably the best lead, I think it is possible the killer was just someone acting alone. I think it is possible a single male drove around and offered lifts every so often on weekends and just got lucky, from his point of view, on the three occasions the young women went missing. I know the police called for anyone to come forward if they had ever been offered lifts from someone in Claremont, but I just don't think that is a question that would be answered, with the passage of time, with accuracy. It would be such an innocuous thing if a nice person just drove up and offered a lift and you declined. You wouldn't remember that 5 second interaction, especially if drunk, or if you did, if the person seemed nice, you would probably think, 'well, that person would not be the killer, so best report nothing'. Also, this theory probably explains the gaps in time between the abductions of the women, them being based on, as it were, luck.
Following this line of thought, I'm trying to place myself in Ciara's shoes, who worked for a top law firm, and was obviously intelligent. She apparently knew of the disappearances of Jane and Sarah. Still, if a seemingly nice person drove up and offered her a lift, would she decline because of her knowledge of previous disappearances? Hindsight's good and all, but I think if the CSK seemed genuine and offered her a lift, she would have thought, 'yes there may be a killer, but not this guy'. Humans have a tendency to think things will not happen to them. That is why I don't totally buy the argument that there is no way Ciara would have voluntarily got into a car of someone she didn't know. She may have thought, if at all, something like this will not happen to a person like me, and hopped in.