defensive use of scouts

One tip to try and find and keep entry open is to be active with your starting scout, scout your opponent properly and once you reach feudal age look for the openings (and snipe the waller villager) if you are still unable to get inside, make sure you know what the opponent is up to, if he's doing archers and you walls are hard to get up, maybe play open and add range for skirms instead and then do clean up with your scouts and few skirms. If you have easily wallable map i don't think its that terrible of an idea just to make the fewest scouts to be able to click up (or alternatively transition to skirms, even then you'll get quick up but get more defensive flexibility as archers can't really push vs palisade + skirms behind.
What i'm saying is, rather than defending walls with the scouts try be a bit more active to track the enemy army, so you have more time to react. If thats not possible then might be an idea to just protect the walls but i would encourage to try and be active if possible.

Let me know if this brings up other questions,
Jupe