Argentina just shows Messi is nothing without Iniesta, Xavi around him
Actually Messi is the 4th best goalscorer in the history of Argentina's national team with 31 goals. This year he scored 14 goals in 14 matches, including a hat-trick against Brazil. He won a a Sub-20 world cup, the olympic gold medal and reached the final in the Copa America. All this being only 25.
If Xavi and Iniesta have more titles is because Spain's team is a lot better than Argentina's. Messi has been playing under some terrible coaches like Batista, Basile and Maradona. Now with Sabella that isn't brillant but at least is a good coach he is showing what he can do.
It's actually the other way round. Xavi and Iniesta were playing at Barca for a long time and they started being considered among the best players in the world when Messi reached his prime. Messi makes everyone around him look better.