+Increase time taken to relay orders (Then it is not "immediate")
Let's say we have a friendly unit A spotting an enemy, the player notices that and immediately orders a friendly unit B (a tank platoon) to fire at the location of that enemy (a house). Unit A is a four man scout team, it has no radio, it is not observed by any friendly unit, it is a thousand meters away. Are you suggesting that now any "fire at ground" fire by unit B directed at that house should be delayed by the time it takes for the unit A's runner to reach friendly troops a kilometer away plus the time it takes for the message to travel down the chain of command to the tank platoon commander in the unit B?
But if there is no unit A and there is no enemy spotted at that location a player can select unit B and order it to fire at the exact same spot with a much smaller delay representing the time it takes for the "recon by fire" (or whatever) order to travel from HQ to the unit B. Should there be a delay check every time a player orders a fire at ground order anywhere? Just in case there is an enemy spotted by someone else and the information about it has not yet reached the unit that player has selected for the recon by fire order? A tank platoon commander should be able to quickly recon by fire without waiting for half an hour for the information about the enemy he does not even know exists.
But then this immediate fire at ground order can be exploited by players.
-Decrease the accuracy of indirect fire, accuracy should only increase over time if spotters have visual sight of the target and the fire is sustained.
I think this is exactly how it works in the game right now.
The mechanics can be changed by the developers to make controls more or less effective, you dont need to remove "ground fire". Even with spotters out of visual range you can use map coordinates to make best guesses, even if inaccurate is can be effective for suppression, breaking up of formations and recon by fire.
Do you mean artillery fire? Since you are talking about the map coordinates. I doubt that the artillery fire will ever get removed from this game.