What you are basically saying is the WC Guessed as to the time span of shots being fired. Of course this Guess Work was tied to an unrestricted sight line from their alleged LN Sniper's Nest. Wham-Bam Got You Man. You forgot to mention this entire fairy tale was Altered at least one time upon Tague popping up with his corroborated facial wound.
The WC associate members came up with the timeline by working backwards from the obvious head shot at z313 to the Z frame that shows JFK reacting to being shot through the neck, which corresponded to z225 to the Z frame that shows the sniper had a clear LOF beginning at Z frame z210. That's 88 to 103 frames divided by 18.3fps = 4.8 to 5.3 seconds. The reason the SN was used was due to the overwhelming evidence that pointed to the SN as to were the shots came from. The addition of 2.3 seconds was added due to test performed which showed that was how long it took to operate the bolt. Tague threw a monkey wrench into the original FBI conclusion that three shots had hit their mark with the first hitting JFK, the second JBC, and the third and last hitting JFK. IIRC, the SBT was already formulated before the Tague wounding became known to WC associate counsel investigators so it would not have affected the timeline of the shots because it was already known they couldn't account for where the bullet that first hit JFK went. So it still would have gone first shot hit both JFK and JBC, second shot missed, third shot hit JFK thus the 4.8 to 5.6 second timeline became moot from the outset of the WR becoming public. Years of experiments trying to prove that three shots could have been fired to duplicate the alleged Oswald marksman feat were a waste of time and served only to mislead the public to the real circumstances that affected the correct timeline of the three shot sequence from the SN.