This whole conversation is interesting. I am the first to have put a lot of focus on Crr for tire selection
According to Xaviers’s data the new Corsa will get a 70kg rider at 5h IM pace less than 2 watts of saving on RR
No consideration of aero (2 watt is easy to find)
No discussion of proper tire pressure (2 watts trivial to find)
No discussion of width which impacts the above 2
Then we needed to quantify flat resistance
For me, selecting the two tires based on CRR is like ordering a double big Mac, supersizing the fries but feeling good because you ordered a diet coke 
Maybe there needs to be an article on optimizing the whole wheel. As a wheel supplier, maybe Xavier’s up to it
A anecdotal note here re:puncture resistance. The word is that Ineos used the GP5TT’s for the whole TdF and didn’t suffer a single flat. Based on past experience with the Vittoria Speeds, I’m not sure they’d be up to that. I know the construction method has changed a fair bit, so I may be speaking out of turn. Also UAE was using the TT almost exclusively as well.
Spent over a week testing on roads like this with the GP5K and 5kTT. Pressure from 50 to 90PSI, riders from 60 to 75kg, 25,28 and 30s. Over and over, not one flat