I hope so atleast.
As far as it was mentioned (or just guessed) a settlements needs to be a certain size in order to get attacked.
If that's the case:
My Settlement Plan:
1. small shack (for my stuff+workbenches) (maybe gas station?! Hopefully with cellar!)
2. upgrade automatic turrets (if we have one)
3. Fence around defenseline 1
4. Settlerstuff (shacks and such)
5. Automatic turrets
6. Wall around defenseline 2
7. build outskirts for travellers/caravans
8. automatic turrets / sniper/spotter towers
9. simple fence to mark the city entrance / defenseline 3
One will say stolen, but yes, Vault City had nearly the same design. Atleast on one side. 