Terrains hurt my brains

I've been playing around with the terrain for the first level and it's completely out of control!!!

I wanted a large playing area because the user can fly anywhere quickly and so I generated some huge terrains in TGEA as seens below. They are around 10k x 10k. I flattened an area to put buildings in it.

Only problem is, the flattened area is miniscule and I couldn't find it! Also trying to world build something this size would be a nightmare but it has given me an idea.

I will use the one large terrain (well I'm scaling it down now) and set up 10 areas of operation. From there I will world build per mission. All missions of the final game will be on the same terrain so I can make a compelling game with less assets.

I needed to scope it down to make the deadline and I think people will like the game this way anyway. Here's the pics.