To understand the HSCA, you must understand that the HSCA consisted of several panels and teams, such as one panel for the medical evidence, one panel for the photographic evidence, one panel for the firearms evidence, a team for the Oswald-Mexico City evidence, a team for the organized crime evidence, etc., etc.
The forensic pathology panel was a sad joke
The photographic evidence panel was not much better, although the PEP did acknowledge the photographic evidence that someone was moving boxes in the sixth-floor window less than two minutes after the shooting--obviously, this could not have been Oswald.
The organized crime team did a great job, absolutely outstanding work. They destroyed the WC's portrait of Jack Ruby and the commission's myths about Ruby's shooting of Oswald.
The Oswald-Mexico City team did a fantastic job. They found clear evidence that someone was impersonating Oswald in Mexico City.
The HSCA's review of Jack Ruby's polygraph was crucial because it showed the the FBI examiner rigged to help Ruby to avoid failing the test but that even then the test contained indications that Ruby lied.
The HSCA's acoustical guys were superb and discovered scientific evidence that at least four shots were fired during the assassination.
In most cases, the panel chairman/team lead greatly influenced how well the panel/team did. Baden was a train wreck as FPP chairman.