The Elixir (cloaking unit) has no range and cloaks only the hexes next to it!
Every unit which is right adjactent to an Elixir can't be seen by the enemy. But it does not cloak units which are 2 hexes away, there seems to be a mis-understanding about how the Elixir works.
Not even an enemy buggy with 1 field between him and the cloaked units can see through the shroud. The only option to reveal a unit protected by the Elixir is to move right next to it (touch), but this gives them a surprise attack bonus.
normal combat
both units fire simultaneously. Then each side gets it's damage subtracted.
surprise attack
The cloaked or otherwise not visible unit, gets to attack first and fires all it's guns. Then the damage is substracted from the ambushed unit, and if it has any health left, now comes to fire with the remaining strength.
The surprise attack is quite powerful on Quasars (1-3 artillery) up to the UMX-1 launcher, because it will most definitely wipe out anything before they get to fire. Additionally, surprise attacking units can fire even when their minimum range (like 5 for the UMX) would not allow them otherwise.
1) For example: A Samurai-3 tank which moves right next to a cloaked UMX-1 launcher will get totally destroyed in the surprise attack, leaving it cloaked (since the tank didn't survive).
2) Another example: Two dragon helicopters and an Elixir set up an ambush, waiting for unsuspecting technotraxes. The first trax arrives, gets a surprise attack from both helicopters, and vanishes. Since the enemy didn't even see the helis, he sent another trax and another and voila! The 2nd helicopter was at maximum experience (double wings) in round 1 of the map
