I live at the bottom of Saint Panthaleon, I know these roads very well.
The descents of Saint Panthaleon and Col de Joux are quite easy, it is very difficult if not impossible to make the difference downhill.
The long stretch from Antey to the bottom of Joux is large, has almost no bends and the wind will very probably be blowing against the riders.
This should discourage attacks from Saint Panthaleon.
Joux is quite an easy climb, large road, regular gradients, not the climb where I would expect much to be honest...
The first few kms are the hardest ones, if someone wants to attack should not wait too long.
The hardest gradients are found in the second half of the climb, but that section is quite short, less than 500m I think.
The stage design is a bit meh, the best finish would have certainly been Tsecore + Joux, the perfect combo of hard climb immediately followed by easier climb.
With this design I am not expecting much, I fail to see where Yates/Carapaz could make the difference.
The perfect launch pad is Tsecore, but it is too far from the finish.
The second opportunity could be the last 2km of Saint Panthaleon, but who will dare given the unfavorable descent that follows?
If I were Carapaz, I would try to ride the first two climbs with the team as hard as possible and fire the first bullet at the bottom of Joux.
Best case, you can get separation from Del Toro and be followed by Yates/Gee/Pellizzari.
If It doesn't work, second bullet at the hardest gradients.
If at that point Del Toro still follows, fold and think about Finestre.