Peace has reigned for so many decades among the various nations of Earth that the average foot soldier has never seen combat, and a general deterioration of skill afflicts soldiers to an all-time low. Okay.
We'll assume that there has been no cold war, no rebellion, no organized crime, no terrorism and is in short a human utopia from which no worthwhile tactical or military skill could spring forth. Great.
Oh, and no sharpshooting, Olympic, target practice, hunting or general handling of firearms which might generally teach an individual which end goes where. No problem.
Even the best of the best, the elite, soldiers sent by UN member nations as the last best chance of defeating this alien menace, are men and women whose weapons handling skills are characterized by words like "mediocre" and "average." (Which would imply they rank poorly even in this future of pointless and worthless soldiers.) Fine.
An elite PHALANX sniper can miss an enemy while firing from a standing, unsupported position from four-hundred yards with a scoped, high-power rifle. Understandable.
This same sniper can somehow put this same round through the back of another elite PHALANX soldier, requiring the weapon be pointed THREE FEET in the wrong direction. Now we're stretching belief.
That this grievously wounded, elite PHALANX soldier, with less discipline than I would expect from a member of a high school marching band, would then fire a grenade at the sniper, just takes this whole situation into the realm of comedy.
Is it possible to have a six-pack attachment we can place in our inventory, to round the experience out? Perhaps the dropship could be replaced with a still-running 76 pickup truck with big mud tires?