One thing to remember is that this is supposed to be a GAME. The purpose of a game is to create the feel of the situation without overly burdening the players. EiA as a boardgame did this very well. While some improvements can be made without fundamentally changing the game (such as what happened from the ADG version to the AH version), some changes would alter balance too much. It would take many playtesting sessions to reveal every possible repercussion of a rules change. Perhaps some modifications could be included as optional rules, with a warning that all possible outcomes of this rule have not been tested.
As for people that are worried about "realism", runaway realism can ruin a game. Those of us old enough to remember the heyday of boardgaming with SPI might remember a monster simulation called "Campaign For North Africa". In this one, you had to keep track of things like individual tanks, planes (even pilot ability), trucks, etc. for the entire North African campaign. A unit equipped with Panzer IIIJs had more combat ability than one with Panzer IIIFs. You also had to keep track of every ton of water, supplies, ammo, etc. and truck them from ports to the front lines. While I believe it was tounge-in-cheek, there was even an optional rule called the "Italian Pasta Rule" where Italian units needed an extra water supply point to take into account cooking pasta.
Almost every rule added to create "realism" hurts playability. It is the developer's job to balance the two and for a game of the scale and length of EiA, I feel that to error on the side of playability is the correct choice.