Yes if successful they see all other troops but not heros of others. Hero of only the defender is seen rest heros stays hidden but troops of all others are seen and other trick is that if u want to know if the defender has reinforcements then send 1000 of each t1 without hero and see how many u can kill and if the ratio is higher then it is not a trap and less then trap. i do the same and m pretty good at it by now, doing that since a long time now works everytime.