Nobody knows for sure. They were both soliders, once with the Colombos the other with the Genovese... so why in the world would Scarpa know MUCH more than Valachi?

I believe those charts and a lot of other info came from MANY other FBI sources, some of which are probably not even known today, including illegal wiretaps, etc, etc.

All these were "put into" Vachali's mouth at the big commitee to make it appear as he was a key member of the WHOLE Cosa Nostra, not just his family.
Also Vito Genovese is known as "Don Vitone" there. I think that's just a name Costello called him, if anybody else in his family did it, I'm sure they'd be ground fertilizer the next day.