Remember: Before knocking Noodles out, Max tried to convince him TO STAY AT THE SPEAKEASY and only after Noodles refused answering" Eveywhere you go, I go" he decided to beat him.
Clearly Max had made the sacrifice of Cockeye and Patsy, but not of Noodles.
Its a great proof of love ! 
i stil couldn't understand how Max could have sacrificed Pasty and Cockeye, childhood friends and associates during ten years in their gangsters lifes.
this characters were also always sympathic in the film (during thier childhood and after that during the "parodies" of gangsters film),
it's hard for a basic spectator to see them killed and totally forgotten after that...
well, they were gangsters, violent etc... but why Max killed them?
for me it's not understandable!
Perhaps Leone Wanted to show that old (gangster ) cinema is dead through the death of these characters of gangsters???
Leone wanted to show that commercial cinema killed the great cinema ??
after that :
why Max later have paid a great "mausolee" (it's a fench terme means a great tomb).
How could kill his friends and after that, made for them these rich great temple???
a temple of the old cinema for Leone

this film deals with friendship...
between Max and Noodles..
why Patsy and Cockeye in the end didn't signified nothnig for Max and Noodles???
to show that a true and strong relation can only happen between two people

Noodles and "his mother" or "uncle" Max