But that isn't really a concern because NPRs will not do that and if a human player wants to exploit and game the system, they are free to do so in a single-player game. After all, if you're going to the trouble of creating thousand single-soldier formations just to protect your AA from NPR fighters, you might as well just use SM to manipulate the battle in the first place - it's much faster and far less work.
But you can't cloak starship weapons, so why would you be able to cloak surface-based weapons?
Starship weapons cannot be hidden because there is nothing to hide them in space. On planet surface, there is. The atmosphere can distort where the laser beam came from, terrain features might enable rapid shoot'n'scoot operations. Counter-fire isn't instant even with computer assistance, because there is always delay and lag: you have to observe the AA fire, then calculate the area where its coming from, then make a decision whether to fire, then get into a firing position, and only then is your counter-fire moving at the speed of light. Fighters operating on a planet are immune to fire from STO and space ships, meaning that they are operating at low enough altitudes that terrain and curvature come into play, so the same things work for the benefit (as well as hindrance) of AA.
Just as an example, Serbia managed to preserve the vast majority of its ground forces, as well as keep her air defence network working, throughout the 1999 Kosovo war. Despite the fact that they were facing the largest and most technologically advanced air power in the world. One reason was that NATO really wanted to avoid casualties, but the Serbs also did many things right. So while sensors get immensely better in Aurora-future, there is no reason to assume that the defensive measures and tricks would remain stagnant.
Basically, I want to avoid a situation where one player can send a bunch of fighters against a planet, divide them on generic ground attack and SEAD missions and them leave them for six months.