No inertia means characters can move unpredictably enough at any range to completely avoid conscious human aim which is >150ms. A character can be strafing left, and within 150ms, strafe right over a meter, only aimbot is capable of a 100% hit rate on 0 inertia PMC's.
The solution with the game's meta? Have a minigun shooting AP. Miniguns niche in war is throwing enough shit at a wall hoping one turd sticks, not what videogames show. If a 3000rpm gun sweeps its gun across a plane and is on target for 50ms, it will score 25 hits. If that gun is shooting 650 rpm (Like the shitty 5.45 AKs) it will only score 5. This also applies to shooting characters in EFT that have no inertia, this is why 5.45 AK's are shit guns, and why the Mutant/HK are the kings of PvP. The mutant is inferior for headshots, but it will kill a thorax faster than an HK, the HK shoots far faster so it will average more hits however, and so it is a superior headshot laser for someone with good aim. The Mutant is better for players with inferior aim.
If inertia is realistic enough to make every player that takes every fight bitch, meta guns will be like taking a sledgehammer to drive nails. Semi auto will be entirely viable in meta PvP like labs (only for players with top aim) because fighting will no longer be about having the best possible gun for killing people by sweeping across their general area with full auto; because it will be possible to properly aim at those players to score a higher hit rate with conscious aim.
