I suppose what I actually meant with my fog of war comment was more like this.
For sake of argument, a scout can see a standard vech say 10 units of distance. Now if a camo/ECM/stealthy vech (however it is stealthed up, doesn't matter) approaches the scout, the stealthy vech only shows up (or is "sighted") at 5 units of distance from the scout.
And I'm not trying to imply that scouts are the only ones that can detect stealth. I just picked a scout for argument's sake. You can insert "Laser/Mic Lynx" if you'd like. But then if a lynx can only "see" for 6 units, then it sees the stealty vech at 3 units. This could also affect targeting. So a stealty vech can get closer to a thor or something.
So now there's no requirement for special research. Stealthy units can still be seen and targeted. And they don't become uber weapons for which spamming would be a problem.
(And stealth doesn't need to cause a 50% reduction. Again, it was just to make a point.)
So here, stealth can be radar reflective, ECM based, or just camo paint. All of these things could cause a computer AI problems for detection and targeting requiring a combat vech get closer.
(Dang, that seems long... :yawn: )