1) If Martinenghi swims 0.01 slower, he doesn't medal.
2) In the men's 4 x 100 free relay Italy might as well have finished 4th (behind GB and the US)
3) In men's 200 free the 10th place was a huge success for De Tullio. You shouldn't forget that multiple faster guys flopped or didn't even compete (Märtens, Pan, Marchand).
4) In men's 200 fly you shouldn't forget that Milak didn't compete, otherwise Razzetti would have been 0.5 seconds away from the final.
5) In men's 200 IM multiple faster guys flopped or didn't compete (Wang, Qin, Kos).
6) Not sure if Franceschi would have made the final if McKeown, Pickrem, Wood and McIntosh would have competed/not been disqualified as well.
7) Poggio was unlucky, not sure how close he would have been to the final if Peaty and Imoudu would have competed (not to mention the two russian guys and Shymanovich who were missing as well).
Before this year i would have expected Italy to definitely to better, but in my opinion 4 medals is pretty much a perfect result for them given where they are at right now. I would give the following italian athletes a chance to medal next year:
Maybe Miressi (100 free)
Maybe Galossi (400/800 free)
Men's 4 x 100 free
Maybe men's medley relay
Martinenghi (100 breast)
Ceccon (100 back, maybe 100 free)
Quadarella (1500 free)
Pilato (100 breast)
I think 2-6 medals are realistic in my opinion (Quadarella, Ceccon, Martinenghi + X).