There's probably some info out there somewhere about their personal relationship but it brings up an interesting dynamic in the Gambino family I would like to better understand. You have the Calabrian / Mainland faction that was based out of Red Hook area in Brooklyn who took power in the family after murdering the Mangano brothers who were Sicilians from Palermo. Scalise also being a Sicilian from Palermo was likely, though not definitely to my knowledge, more aligned with that faction of the family. I'm not sure if Gambino was more motivated by Scalise or Mangano (I would think Mangano murder) but ultimately the Sicilians made their move and took power back. Anastasia was pretty ruthless and I read Valachi say a massive gambler so he was probably pushing to get money in to himself too. Similarly Castellano also a Sicilian murdered by non-Sicilian members of the family (Gravano is Sicilian descent but not a long term family-lineage member). The Sicilians have since re-gained control of the family albeit there was no real revenge for the Castellano murder on their part I don't believe..
It's an interesting dynamic in that family that continues to today
Gambino was likely not the one who had Anastasia murdered. Alfredo santantonio, a made member in Charles Dongarra's crew furnished a likely story for the murder it goes as follows:
Anastasia plotted to kill Joe Biondo, Joe Riccobono, and Charles Dongarra. Family captain Joseph Franco was made aware of the plot somehow and then told the three men who then plotted against Anastasia. They sent member Stephen Grammauta and associate Joe Cahill to murder Anastasia and they did. The murder was brought up at Apalachin, but they were
"acquitted" citing self defense as their reasoning. Jerry Capeci reported the shooter being Grammauta and Arnold Wittenburg. Grammauta is also confirmed to have been a shooter by Gambino captain Michael "Mikey Scars" DiLeonardo. Stefano Magaddino also sheds some light on the matter saying that Gambino was appointed by the commission because he was consigliere, not because he just made some powerplay and killed a boss.
