Yes, Messi could have scored five goals and Nigeria stood no chance. But Argentina were never under pressure when they had the ball, with a lot of time to pass it around and wait for Messi, or Tevez, to come back for the ball then run practically unencumbered toward the goal with it. Veron was awful, could not make a good pass with all the time in the world, turned it over a few times while being under no pressure whatsoever, and is entirely incapable of passing while running--he walks with the ball. He slows Messi and Tevez down as he prefers to pass sideways, so there are very few through balls coming from him. Alternatively, he can drop a long ball, but with Messi and Tevez playing deep only one who could really get it is Higuain, who needs three clear chances for every goal he scores. Higuain was dreadful today, could not connect with Messi, and Argentina picked up with Milito on the pitch.
While Maradona has a lot of options up front, he has very few in the midfield. There were very few midfielders on the bench who could replace Veron. Maxi Rodriguez plays on the right side, while Pastore is young and untried. Veron is by far the weakest link and is likely to buckle under any serious pressure--he might have a hard time against South Korea, never mind playing against England or USA in the quarter finals (if they even get there, past the winner or the runner up of Group A). In the 4-3-3 formation (which was really 4-3-2-1 with Higuain at the top), the midfield of Mascherano, Di Maria and Veron is very creaky and slow. Everything depends on Messi or Tevez coming back into the vacant space left by Veron to get the ball. Once that midfield is crowded and the other team puts pressure high up the field, they are going to have major, major problems, which will lead to many other problems being exposed--say the slow defence with Heinze and Demichelis and Samuel (who nearly gifted a goal to Nigeria).
Everything then depends on the front players--they will need to create and score a lot of goals out of nothing. Messi is certainly capable of creating something out of nothing--which was obvious today, again--but as they progress it will be harder for him. In another words, Messi needs to be the Maradona of 2010 and win it singlehandedly. If it happens, it will be memorable. If the story of 2010 Argentina is Messi, they might win it. If it is Maradona, they're screwed.