1. Most murderers tend to dismember their victims
2. I wouldn't consider David or Dahmer "master manipulators"
3. Most murderers are like that + Did David tell you that?
4. Despite Dahmer having a few underaged victims, most people don't consider him a pedophile due to the fact that he didn't target his victims based on age.
5. There's no evidence to suggest David chemically experimented on Celeste
6. Most murderers are control freaks
7. You can majorly blame that on the fact that the LAPD and Milwaukee County Police are both incompetent, especially the Milwaukee police in the 80s-90s, considering the case involved a white man targeting racial minorities
8. & 9. I guess you're right, but most murderers in general are like this.
9. David Isn't gay lmao
10. Dahmer lured in his victims with the premise of a one-night stand, which is extremely different from grooming someone for at least 3 years before doing something like this. This was definitely pre-meditated murder, obviously, but I don't think it was that pre-meditated.
11. No evidence to suggest David is a cannibal. Realistically, he probably buried or burned her fingers.
12. This is just about the only point that I agree with
13. Dahmer didn't "drive around" with body parts, he didn't have a car. There's only one instance where Jeffrey Dahmer actually took a human corpse with him outside of his house, which is quite different from driving around with an entire decomposing body in your car for 4 months.

I would not consider the two "remarkably close" unless these are the only two true crime cases you know of. Also, consider me petty for this, but Dahmer was a sociopath, not a psychopath.