What imbecile was responsible for that final battle scene? Permeated with tactical errors, the final battle in the fictional world of Wakanda has got to be the most teeth-gnashingly horrible battle put to screen. Honestly, this makes Return of the King's Osgiliath battle look like genius. Let's look into the what mistakes they made.

The location: The battle takes place in a fictional country protected by a force-field shield (think Gungun army from Star Wars), inside the circular shield is a city in the middle with grassy plains around it, but still inside the shield. The battle started with the enemy troops landing outside the shield and being forced to walk through onto the grassy field. Apparently the Avengers decided to meet them there, on a flat, wide plain where the numerical advantage of the enemy would work most to the hero's disadvantage leading them to be easily encircled and slaughtered. The Avengers do not take advantage of the city's walls and mounted cannons we can clearly see behind them, nor do they use any aerial fighters excluding the ones among them who can fly; no planes or helicopters are used, nor is there a reason given as to why not.

The weapons: I have already stated the moronic absence of aerial superiority, but that is not the end of it. Despite being an advanced culture facing a haphazard mob of monsters armed with nothing but fists and teeth, the Avenger's army is outfitted for the most part with spears, swords, and shields. There IS one smart guy in the group, Bucky Barnes, who systematically machine-guns down the enemy without letting them get near him. That was the smart thing to do, but the rest of the heroes charge the mob head on, allowing the enemy to take the most advantage of their weapons (fists and teeth).

The organization: The Avengers don't have any battle plan or trap of any kind; the plan as far as I can figure is "Go get them!". There is no formation of any kind, besides a homogenous mass of soldiers charging en masse into the arms of the enemy. Why this is, we don't know.

The scale: One thing that catches attention of this battle is that the Avengers treat it as the battle for the dominion of the earth. Indeed, if the enemy were to win, half of the universe's beings would be wiped out of existence. But if this battle was indeed so important, why wasn't any nations army there? Granted the US government would be skeptical sending troops over to an African country to help spandex sporting soldiers, but as seen in Captain America Civil War the Government DOES take the Avengers seriously and would likely do even more after a giant spaceship appears above Manhattan previously in this film. I digress. Having only a platoon of Marines could dramatically alter the battle, what with machine guns and explosive grenades. Heck, the enemy army could be wiped out without even reaching the city walls using a couple Apache helicopters armed with miniguns and rockets. Once again, these enemies are armed with only fists and teeth; any ranged weapons such as guns would completely wipe out any charge without a casualty. (There's a reason WWI ended mass charges, it was a bloodbath whenever someone tried). Somehow drug cartels can get mounted machine guns, but "Earth's Mightiest Heroes" can't? Just imagine what modern tanks and a squad of heavy-machine gunners could do to Thanos's pathetic army.

The decisions: The orders given during the course of battle by the Avengers are also failures. When the monsters begin to force their way into the shield and encircle the Avengers. In response to this, the Avengers order to open a portion of the shield to center the enemy's forces so they can kill them better. Now a more successful tactic would be to maintain the shield and retreat to the city, killing any of the enemy that make it to the walls, as only a couple enemies get through the shield and it can be seen that walking through the shield burns and amputates the monsters. However, if one does want to open the shield, it would be better to open and closing it systematically, using a military tactic known as "Defeat in Detail". This tactic allows smaller armies to defeat much larger armies. In this case, the shield would open, letting a small portion of the enemy army into the inner circle, and then close it, trapping a small army against the Avenger's much larger one, allowing the Avengers to slaughter the enemy with near no casualties. This could be repeated as many times as long as there is still an enemy army standing.

Oh yeah, and don't even bring up the extremely powerful superpowers that some of the heroes use once and never again.

And Tony Starks Nanotech is the stupidest thing I have seen in one of these movies by far, and they don't even try to hide it's CGI.