I think there is 2 versions of Cane Corso but I think they are more similar than people argue!
The Italian ones are neurotic and fear-aggressive while American ones tend to be better. The Italian ones turned out very nervy and unreliable when tried out on pigs in Australia and got dropped completely with a few scattered here and there.
They're similar physically but not mentally.
Still both don't really have the good temperament of say a Neapolitan Mastiff or Presa Canario or Bullmastiff etc. etc.
The Cane Corso was never going extinct, that's a myth. It was a bulldog misused for war, there were still the same exact dog around. Maybe not under the ''Cane Corso'' name but it's still a Cane Corso. Maybe with a better temperament at that.