As a relative newcomer to the game Ive learnt that IF you get hit by scout spam early, you biggest ally is build speed. Scouts have to be 3v1 or more to be effective. Once engaged the enemy has to build more and faster and you only need to build 1-1.5 for every three.
That being said, if the enemy has 30-50 scouts in your HW early game, then you missed something before they got there.
However, its fascinating to see the way scouts can be used.
Questions on scouts?
Can you set them to move in a permanant patrol around 4-5 planets. Set it and leave them go round and round?
Is there anyway to determine where they will go to autoexplore? If the map is 50% controlled by you, will they avoid your 50% and mostly move around enemy territory? Thus as you own more of the map, they only move around smaller areas?