Vincent had the much easier role - his "script" was already prepared for him from the WR.
Bugliosi happened to agree with the evidence and facts contained therein. He's nobody's fool.
He did not deviate from script.
Spence failed to do his homework and cast doubt in the minds of the jurors.
The outcome meant that everyone could sleep easy again.
Folks saw the outcome when an actual prosecutor and actual judge examined the case.
Most of the junk-contentions from CTs ("fake", "prove it", "we don't know", trolling, spamming, gut feelings) wouldn't have been admissible. Spence tried one of your tactics: show Oswald as the family-man Magoo, or Saint Patsy. It was creepy and embarrassing.