Building in Eden will give you substantially more control over the placement of fixed objects such as buildings, h-barriers, sandbags etc. Our modpack includes Eden Enhanced which makes it crazy fast to build compounds etc with perfectly straight walls etc. Building something in Eden which is AI-heavy is a lost art these days, as it doesn't run simulation in real-time, it's hard to know for sure how the AI will react in any given situation, let alone making that AI react to players.
I generally build the basic structure of the mission in Eden, with all AI going down in Zeus.
While I don't have heaps of Eden content (because most of what I build is S-4 classified), but you can find some of my Eden stuff on my Youtube:
https://www.youtube.com/playlist?list=PLI-_oDhaV6vxTxf9p8iZ8rH9ch-V6JnUcWhat you'll see is that some of what is very quick to do in Eden would be a pure nightmare in Zeus.