Humm, so I take it you find the idea that Oswald was impersonated to be some wild and specious theory? Are you aware that the two HSCA investigators who investigated Oswald's activities in Mexico City (Ed Lopez and Dan Hardway) came away convinced that someone was impersonating Oswald in Mexico City? Have you read the Lopez-Hardway Report?
How about the several reports from credible witnesses, one of whom was a doctor, who reported seeing Oswald at certain locations in Dallas when the real Oswald was positively known to be elsewhere at those times? Let me guess: All the witnesses were "mistaken," right?
Nowhere in the report does it say they were "convinced" that an impersonation took place. The document says "the possibility" of an impersonation cannot be dismissed
not that one did occur.
Here is what it
directly says about a possible -
possible - impersonation (this is from the section looking into the question):

Saying "a possibility cannot be dismissed" is not saying they were convinced one took place.
Report is here:
https://www.history-matters.com/archive/jfk/hsca/lopezrpt_2003/html/LopezRpt_0264a.htm