Danito, are you suggesting that if Tom and Michael had threatened Woltz and Moe, respectively, the outcome would have been different?
Well, let's analyse it.
1) The Tom-Woltz-Situation: In fact, Tom is threatening Woltz, though not openly. When Woltz says in the beginning: "Are you trying to muscle me?", he really gets the point. That's what Tom, the smooth talking sonofabitch is trying to do. Later, during the dinner, Woltz even refers to the bandleader story. So he just underestimates Corleone's power, while Tom had underestimated Woltz' vanity. Tom's strategy was half successful, he had to show Woltz the instruments.
2) As far as I can see, it's not clear what Michael's visit in Vegas was all about. If it was only about the hotels and the casinos, if he had only come to "buy Green out", then he behaved like a beginner. Why making Moe an enemy? He knew that Fredo was weak, so why didn't he talk to him before he spoke to Moe Green, so that he could be sure that Fredo would keep his mouth shut? Why did he mention that Green slapped Fredo? UNLESS: All that was meant to show that Michael was weak. Also, Michael WAS in fact threatening Green. When he said: "I'm leaving tomorrow, think about a price.", it means he doesn't really care about Green.
