I agree that spotting is strange and maybe a little broken (infantry vs. tank, tank vs. tank, tank vs. infantry, ect). I brought this up on the inner boards and we hope to look closer at it later on down the road. I think that buttoned tanks see infantry too easy and infantry have too hard a time seeing tanks right in front of them.
I have had too many instances of tanks or troops just not seeing something right in front of them for it to be cast off as stress of combat. Once in awhile is fine but it happens too often. Tunnel vision and auditory exclusion aside, a tiger in front of you at 10 meters in the middle of the road is HARD TO MISS.