There is an issue with fence foundations, some people are cheating and this is very hard to raid. See the pictures below. it is not possible to put bombs on fence foundation, so it is possible to use splash damage for fews doors, but not after.
I have the solution : If a fence foundation is not attached to a foundation, then stability = 0 and it is destroyed at server reset.
I don’t think this is a cheat in any way. It’s certainly difficult to raid. Fence foundations work just like foundations for stability the must be supported by another fence foundation or a game structure. Walls, ground and so on.
If they should make any change, it should be the ability to place a bomb on the fence foundation.
As for raiding the build in your picture there are explosive arrows that could be used against it.