I've seen Saylor in person 3x and Caroline on video in several highlights and a couple of complete games.
I thought and still think that they are very similar. Extremely similar, in fact. Both had/have guard skills and had fairly recent growth spurts (9th-10th grade) and are now 6'2". In addition to being the same height and having similar builds, their games are quite similar in that they both do everything well. Saylor plays in a relatively low-level conference in high school and literally plays positions 1-5. She jumps center, plays in the post on defense, and brings the ball up the floor. She had a triple-double late last season. She does everything well: defense, shot-blocking, passing, ball-handling, and shooting from all over the floor. Her form on FTs is very good. Her 3-point percentage is decent and she shoots from 20-25', as does Caroline. Saylor could improve her left hand, especially on layups, as she tends to shoot them using her right hand, regardless of the side of the basket, but does so quite effectively. She has no appreciable weakness. She's highly versatile, plays hard, and has a good hoops IQ. One thing Saylor does very well is to play "free safety" when her team presses--any pass that's in the air more than 2 seconds winds up being a steal and a likely hoop for Middletown. Her instincts and anticipation are excellent, and she's long and can leap. She'll fit nicely into a full-court press.
Finding differences between Saylor and Caroline seems like an exercise in splitting hairs. I should note that Caroline had a knee injury and recovered very well. In recent play, she has drawn rave reviews and "blown up." Some ranking services have her in the top 5. I think HG moved her from #31 to #5, or something like that. Saylor, in contrast, was rehabbing from post-season hip surgery during the spring and summer, so she didn't play for months. Perhaps as a result, she slipped to HG #30. I suspect both belong about #5 and #15. The recent info on Caroline suggests she's an elite shooter. Previously, I would have rated both her and Saylor as "very good" shooters. Caroline may now be in the "great" category. I'll be interested in seeing how her shooting compares with Azzi's, because Azzi is in the "Curry/Thompson" category that Geno mentioned recently. So, Saylor's advantage over Caroline is that she seems a little stronger; Caroline's advantage may be that she is an even better shooter.
In terms of the fit, I think both Saylor and Caroline can play the 2, 3, or 4. Geno has already said that Saylor can fill in at multiple positions. He also mentioned Caroline's versatility.
I'll see Saylor if Middletown has a season and games are open to the public (and the same for Azzi). I'm looking forward to seeing all 3 plus Amari in Storrs in 5-8 months.
I believe that both Saylor and Caroline were their respective State's Gatorade POY as juniors.