Except,even my sancturary hills has been completely damaged(every turret,every crop) and most of food taken from workbench,due to an attack i wasn't there to stop.I WAS there,killed everything,attack didn't end,slept few hours,walked about,no enemy spawned,so i fast travelled away.Came back later at attack fail.
All my settlers are sporting lasers and assault rifles(modded)heavy armour etc.
They do not defend anything while you are not there.If you are not there,you will always fail,and stuff will always get wrecked,no matter how tricked out the settler,no matter if you have a 500 defense rating and turrets covering every area,no matter if you have walls and guard posts up the wazoo.
Sometimes you come back to less damage(i happen to think this is completely random) and sometimes due to the time it takes you to travel to a settlement things may have already auto repaired.
There is zero you can do to help your settlement auto defend once attacked other than travel to it and take over manually(which is bloody hilarious because usually when i fast travel to a settlement under attack the attackers die in in less than 3 seconds due to my defense set ups,must be my magnificient leadership qualities)
Speaking of defense set ups,my own turrets do more damage to my crops and my settlers than the enemy does half the times,lol...
This system needs to go,and be replaced with attacks having a chance to happen when you travel into a settlement area.These attacks if triggered should come in waves with increasing difficulty depending on where the settlement is,difficulty level and how much food and water it is producing.
As an aside,i'd like to see faction quest attacks,whereby you get emergency alerts from the minutemen of knowledge of a,just for example,a BoS attack coming at such and such a time.You'll get a big quest start message on your screen too.These attacks would never happen in less time than it takes to fast travel one end of the map to another twice over.I was thinking it'd be cool if in beating you they take over the settlement until you can re-take it,but that raises issues like,what do they need to do to take the settlement other than killing you?And what is to stop you just staying put and re-taking it from them within seconds of them taking it from you?