Stronghold might seem like decent idea but it is RTS where it is more in depth but still same thing as walls in AoE2 or They Are Billions for more modern example. You will end up with something mediocre but nothing like real life.
Best solution would be finding a game that allows you to move parts in 3D environment. The best option I can give right now is Planet Coaster. This is a person I recommend for you to see if you are ok with this:
https://www.youtube.com/watch?v=d7WCRb8aqgw
Or just find editor like the Bethesda shit creation tools and toy with them.
And now I will install Sims 3 and finally do my version of painting goblin. Thanks for reminding me to do this.