My take, for what it is worth!
Whilst Sonny's blunder may have been catalyst in bringing Sollozzo and Barzini's plans forward....
Vito made it even easier for Sollozzo, Barzini / Tattaglia by handing Luca on a platter and Carlo did the same with Sonny
Whilst Vito was strangely curious / concerned to find out what Tattaglias had under their fingernails, Vito wasn't worried? about his safety not having beefed up his security
Vito left himself wide open for the murder attempt Vito was slipping indeed
Even though “Solozzo was not a made guy†Sollozzo was still able to approach Barzini [it was Barzini all along] and scored a meeting with Vito, all on his own merit without anyone vouching for him So Sollozzo must have had clout
Perhaps debatable points could be, among others,
- How can the killing of the father not be personal?
- Would / could Sonny still do business with the same people who murdered his father Vito, the same business Vito refused and was murdered because of his refusal
- How would Clemenza and Tessio react to Sonny collaborating with the same people who murdered Vito especially as Clemenza and Tessio actually witnessed Sonny's blunder even though Tom says for Sonny to make the deal if Vito dies
- I doubt any “police/politicos [would] remain loyal to the Corleones†especially with Vito dead and Barzini offering them a lot more money - “all our people are business men, their loyalty is based on thatâ€
- I believe Sollozzo would have already had the backing of all the other Dons through Barzini, Sollozzo's 'silent partner'
- Sollozzo would have kept Barzini and their 'partners' informed about Tom's eagerness for the narcotics trade
- I believe all of Sollozzo and Barzini's plans would have been in motion, loaded and ready to fire - Vito dead, Barzini Numero Uno, drug riches
However the Trilogy theme of under / over estimating each other - in this instance, Vito underestimating Sollozzo, Sollozzo and McCluskey underestimating Michael
