If sight and hearing were all that perception was, then two people seeing the same situation from the same vantage point would perceive it identically...
Ok, let's say perception is both mental and physical. Thats still gives us two mental/mind/brain/social stats against 5 "physical" stats to try to define the basics of our characters. Still unbalanced. But OK, DOS is not about being balanced, it is getting pretty obvious, from feedbacks alone...
And yet there has to be a limit somewhere.
Absolutely. This is a nice "philosophical" subject btw, to which extend make an RPG realistic ? The proper balance between realism, simulation, "fun" ?
Anyways, you are definitely right. Don't add anything. Just make sure that what exists makes sense, will be very nice. And for the most part, we are almost there.
