Yes, I think so.
However, there are many archetypical connections that can be done between characters (not necessarily means that writers wanted to do these connections or know about it, simply there are universal archetypes or characters tropes that repeat themselves)
For example:
Buffy=Supergirl
Angel=Batman (in the episode "In the Dark" of Ats, Spike talks about the Angelmobile as a parody of the Batmobile.)
Angel is also based on Batman, both as dark heroes that use gadgets and the dark city (Gotham/Los Angeles of Angel).
Angel and Bruce Wayne are physically similar and both brooding, private loners, with tragedy in their past who have dedicated their lives to altruistically helping people in need and ultimately, making their city a better place. With Angel being the head of "Angel Investigations," they're even both detectives. Also, there is a relation between bats of Batman and vampires of Angel
Spike and Drusilla=Joker and Harley Quin
Spike and Drusilla are symbolically related to the Joker and Harley Quin, I don't think that writers consciously understood the archetypal similarities of these characters.
There are different versions of the Joker, and the most similar to Spike is the version of the Suicide Squad movie of 2016. (Considering the difference of the year of production of these movie/tv show, writers of Buffy and Suicide Squad didn't copy themselves, but these archetypes of characters are similar and sometimes unconsciously are recreated)
-Spike=The Joker
-Drusilla=Harley Quinn, both women went insane with psychological problems
However, The Joker tortured Harley in order to make her insane, like Angelus tortured Drusilla to make her insane.
It can be said that The Joker=Angelus+Spike because:
The opposite of Batman is the Joker and the opposite of Angel are both Angelus and Spike differently.
Angel/Angelus dichotomy i(n its archetypical representation) is now similar to Batman/The Batman that laughs (a new evil version of Batman).
There are probably many other archetipical connections that can be made among these characters in fiction.