DonAndres you're undervaluing the contributions of both Gago and Mascherano on the offensive side. Gago specially, if fit and healthy, has an excellent partnership and understanding with Messi, better even than the partnership Messi-di Maria.
You saw today Messi and Gago doing a quick one-two in one of Messi dribbles early in the game.
Gago is decent enough to get involved in offensive passing play but that simply isn't the strong suit of this Argentina team. In the knockout stages of the World Cup, they're not gonna be facing the likes of Trinidad so they likely will be dominated in midfield by the better teams. If they try to play a buildup-oriented game they will be pinned back (like they were to an extent today) and those teams will be strong enough to punish them for it.
In tournament play, it's smart to just play to your strengths. Spain isn't going to bank on their front line to do a good job even if they have decent enough players there, they are going to go full out 4-6-0 or 4-5-1 to dominate possession as much as possible and grind out a 1-0/2-0 win. Same principle of playing to strengths goes for Brazil who's central midfield has decent enough passers yet they emphasize wing play using Neymar/Hulk as well as attack minded fullbacks.
Gago may be good at linking up and Masch isn't clueless on the ball but in the end they are a weak link and shouldn't be the controlling force of Argentina's offensive play. Di Maria, Aguero, and Higuain all play for or have played for counterattacking teams (RM and City) and work best in those dynamic scenarios where they destabilize an opposition defense with dribbling or movement. Messi himself can easily thrive in counterattacking play as well given the space he'd have. If you feed the ball to them and let them run at defenses as often as possible, you're a dangerous team that can be a scare for any side in the tournament. If they try and be something they aren't, then it could play out badly.