In the famous tollbooth scene,I've often wondered why the killers used multiple machine guns and a small army of men to do a routine hit. Couldn't one or two guys have lain down on the floor of the booth,and at a signal from the collector,jumped up with 45 automatics?

By the time Sonny would have even registered that it was a hit,he would have been perforated and quite dead.
The gunmen could have still killed the Toll worker like they did originally.

My only take on this is that even though it was supposedly revenge on Sonny for Bruno Tattaglia (hence the brutality and final kick in the face),we later find out that Barzini set it up. Given the prevailing dynamic,I don't think that Tattaglia could wipe his butt without clearing it with Baarzini.So was it Tatt's guys or Barzini's who actually did the work?

If it was Tattaglia's guys,I can't imagine Barzini giving his approval for the tremendous amount of overkill,knowing the extremely negative attention that the massacre would have gotten from the public.

Of course it is also possible that Barzini wanted to strike terror into the Corleone's,and thus decided to make a big splash.

What do you guys think? Any insight or ideas?