I feel like this is one of the rare times I completely disagree with you both. EF don't have the team strength to do much really. They did a fairly feeble version of a Sky train leaving Carapaz to attack pretty much on his own, as he has to always do. They lack the budget to sport a true GC challenge. They are a team of stage hunters.
Carapaz attacks in his usual way and del Toro closes him with relative ease. Del Toro could have snapped closed him each time, but chose to not do so to save his legs a bit on a 60 min climb. However, he never closed Yates who attacked multiple times always leaving that to Carapaz or Gee. I personally didn't understand why Carapaz even closed down Yates twice, since he should have left that to del Toro.
When you are in the leasers jersey without teammates, you will get 1-2'ed by others. You still have to cover attacks and ride. Del Toro never did on Finestre.
He was entirely fixated on Carapaz. Yates may have been the strongest, but he was able to go because del Toro let him go and Carapaz had already closed him down twice and had attacked himself twice. It was on del Toro to defend the Maglia Rosa. There is a good chance both del Toro and Carapaz were stronger than he was, Yates simply benefitted from being allowed to go by del Toro.
Carapaz then again started to ride when Yates overtook him on GC, but was still behind del Toro. Even then del Toro didn't ride or pull and doggedly stayed behind Carapaz.
When Yates overtook del Toro on GC, del Toro still didn't really ride. He was definitely on the limit, but not cooked as he could still respond to Carapaz with relative ease.
Only on the descent and the flat did del Toro begin to ride, when the race was already lost. By then Carapaz had resigned himself to the podium. I'm sure he took it personally, that del Toro only covered his attacks.
It was on del Toro to ride. Sometimes you don't have a great option; you just have to pick the lesser evil. He could have played it cool for a while on Finestre, but when Yates had 30s he needed to start riding. There is absolutely no way around it. That is where you rope Carapaz into pulling as well to defend 2nd and where you say that you two will duke it out on Sestriere for the win, but let's get Yates back etc.
By and large I don't think Carapaz was the strongest rider. I think del Toro was the best and strongest rider among the Giro GC riders. Carapaz does his flashy attacks, but people can often (not always) close him if they just slowly bridge back. Outside of his stage win, he never got true distance off of his attacks.
UAE needed to have a rider with WVA, so del Toro can ride to tempo and cover as much as possible on Finestre. The UAE domestique then neutralizes the rest of the race and most likely del Toro will be able to limit the damage on the last climb and retain pink. Even if that wasn't possible, del Toro needed to ride to tempo once Yates got 20-30s and try and rope Carapaz into helping, which he stupidly would have done or was already doing, just like Gee.
I have absolutely no idea what McNulty was doing this stage or any stage for that matter. Majka was phenomenal yesterday, but outside of that UAE often seem to not know how to race when Pogacar isn't there. Maybe they have suspect tactics at every race, since Pogacar never wins on tactical brilliance, because he never needs to (he is definitely a smart racer personally). Pogacar just goes and wins whenever he wants to and UAE don't really need to scheme up a master plan when he races.
Del Toro rode a phenomenal race. He is an incredible talent, but both he and UAE messed up this stage. When Simon Yates lost the Giro on Finestre it was legs, here it was bad tactics. Del Toro might have lost even with good tactics (to Carapaz), but he'd have at least gone down swinging. Today they lost without truly trying; in so far that riding a 3 week race at age 21 and riding the last two stages at your limit is not trying. But sometimes riding at your limit isn't enough, you have to decide on when to ride over that limit to limit the loss that decides between winning and losing.