JS-
Yes, I agree the Connallys were intelligent and earnest, and their steady testimony, apparently delivered without fear or favor, or axes to grind, tends to rule out the lone gunsel armed with a single-shot-per-bolt-action rifle.
My read of Z-film dovetails with the Connally testimony.
I strongly suspect LHO was the TSBD6 shooter...but that there was a second shooter also.
Caveat emptor, and draw your own conclusions.