Gallic,
from my understanding, clock stops on the 5th rider.
So, you are too ambiguous when you say "was it worth 5 secs" which is inferring to me, that he could stop the clock himself.
AusCycle, Cadel did not sprint. He was in the saddle, and you could see his legs go as he shifted into the 11 cog, and really put down the power in the last k. He separated everyone. It was not a final sprint which decimated and splintered the riders.
Ofcourse, as long as the riders are within one second gap, there probably is the clock stopping on man 1. If the 5th man is outside one second gap, from 4th, he stops the clock.
1 second at 60 kmph is about 17 metres. So if you take 16 metres, the hypothetical best finishing formation, is to slipstream slingshot the riders and get all out of the slipstream but get the strongest guy 16 metres in front of 2nd, and 2nd 16 metres in front, which would be 4x16 metres, which is 64 metres in front of 5th. Purely hypothetical, and not practical.
As is, get all 5 across the line together, sprinting, and using slipstream slingshot and fan out.
Why they did the preparation on a race track, versus a road course is beyond me. The race track is training as science. May as well have done the training as a team pursuit on the velodrome, or sent the riders home by tehemselves to motopace at 55km then hit the win for 20 seconds working in a certain zone and threshold.
The on course, in competition TTT, is one part science. Not 100%. It is one part science, one part art. The team needs to know the parcours, and know their teammates, and how they can handle the course. They need to know when and where they can expend their efforts, and who can expend their efforts. They need to have that knowledge of their teammates.
Most importantly, in the TTT is to use ALL your resources. That is to say, your weakest riders. Unless they are GC leaders, you need to know how to use them. This requires some strategy about 1. knowledge of the time cut. 2. Then a plan about how to use their resources in the formation. Can they really hammer in the first 10kms, go into the red zone, but do some strong pulls, to get the teams average speed up, or contribute to holding it up, not a lower threshold or lower average speed.
So, your 8th and 9th least strong TTTers, how do you use their resources most efficiently, how do you expend their efforts. You do not want Matt Lloyd or Chris Anker Sorenson, being a caboose for 55km. You want them contributing to the pace, then intentionally dropping themselves, because they helped up the pace, that they could never sustain for 55km. The only guys who could be a caboose are your GC leaders, like Frank or Andy Schleck. Everyone else has to contribute to the speed to get 5 riders to the line as fast as possible.
This also presumes, 5 riders can always make the finish faster than 9. Because 9 riders who make the finish proves that 4 riders (assuming non-GC riders) who make the finish, have not sufficiently buried themselves, to add to the pace. They have made the finish, when they could have done a stronger turn at 2kmph faster, over the last 3km. Yeah, this is a fine line, and you need to build into this equation, a security or insurance buffer. But in 2008 Millar was either 6th or 7th man, and buried himself 2km out in the Giro. And he was detached at 1km to go, because he added to the finishing speed. Chris Sutton and one other rider, did work in the first 15kms, because Sutton is a very good prologue rider, with ride capacities over 5km, but he does not have the aerobic threshold as a tter. So they used his strength and abilities to aid with the pace early, and then intentionally dropped himself.
Gotta use more science, and master the art. The Oakland A's brought a different MBA perspective to sport, with their strategy. Like Slipstream they would have mastered this discipline where others fail. Some teams can master the TTT cos they are charging. Slipstream are cleaner than the other teams who have dominance in the TTT. See the book Moneyball, by Michael Lewis, for an insight into strategy, and the weak spot.