Thomas.
He's a 1 peak guy, yes, but he has been getting that peak right in the last 2 years. Of course age can hit him hard at any moment, but since he just rides to get km in the legs mostly until the Giro starts, it's hard to guess if it's already this year. I say no, he'll be ok. Which is nothing more than a guess of course, but Alps seemed to be on the right way. The big amount of TT, not balanced with enough multi-climb stages, but just lots of mountain finishes, will help him too. Even if he's a bit weaker than 23, all the TT should give him a good advantage over O'Connor, who I see as number 3.
Italians? Yep, there's no Nibali on the horizon, but it's not as horrible either.
Ciccone has had his share of bad luck too, if not IMO he would have at least a top 5 finish by now. Crashes, then Covid last year, saddle sore operation this year... he would be starting as a serious podium candidate this year without that. Maybe Vuelta for GC then?
Then there's Masnada who has somehow disappeared after looking good, not sure what his problem is.
Then the 3 mentioned here in this thread, Tiberi, good season so far, have my doubts if he can keep the form all though the Giro, we'll see. But for the future looks good. Bahrain though could have sent Bilbao here, or one of Bilbao/Buitrago/Haig...
Pellizarri and Piganzoli, so far so good, but can't expect much this Giro, a top 20 in GC would be ok. More too of course, but they are young. And not everybody is Pogagar-Remco, slower develpment, they could very well be win candidates in 2-3 years. Or not, wait and see.
Then the guy you are all forgetting: Zana. He's ready IMO. Last year stage hunting, normally this year he should stay in GC. Dunbar, Zana. Problem might be Plapp wanting to stay in GC too, 3 might be too many? Better try to get stages with 1 of them? But let'see, IMO Zana has the quality to ride at the same level as Dunbar in GC. And here that means being a top 5 candidate.