As good as the devs were at attention to detail (like switching the airstrike to a mortar strike for the garg fight at the end of Surface Tension), I feel like their only using Harriers for the air superiority battle was shortsighted. If the U.S. military was LOSING the battle to recover our largest military base from an inter-dimensional alien invasion, clearly recognizing that the fate of the human race, let alone U.S. national security, absolutely depended on it, the HECU would either be augmented with, or entirely superseded by, more Marine units, or more probably, other branches of the armed forces.
Concurrently, even though they were trying to be militarily accurate with the Harriers being Marine aircraft, they're not even fucking supersonic. It is inferred that the Mantas are ridiculously fast, and that the F-16s in the original game can't catch them. I think it is far more realistic for the Air Force to become involved in the later stages out of dire necessity to maintain air superiority than to just have it be the Marines - Harriers can't even move that fast! They should have done F-16 or F-22 models for the end of the game! What do you think? Reasonable or unreasonable?