In that argument in the back of Satriales, once it gets heated, Paulie tells Silvio, "You never know what the future holds, my friend!" Paulie was thinking to himself that New York would probably whack Tony and install him as boss. So Sil better show him a little respect! But...Paulie was fooled.
I took Paulie's comment of the future being unknown as an indirect threat to Sil. Kind of like Paulie saying "When I'm with Carmine & Johnny Sac, I'll personally whack you."
To clarify, the point of my original post was about Sil & Paulie battling for the #2 position and not overtaking Tony. I agree with the other comments here that neither was suited to take the big chair.
