World Composition in a World Compostion

so im trying to get my head around landscape sizes. besides the recommendation of epicgames what makes sense to me i am still trying to achieve a 16 km by 16 km landscape without having either to high memory usage or a to large detail scale.

here are the current numbers i was playing around with:

and i think that 2.0 meters/pixel is just to high.
so i was thinking of how to get around this. and there are a hand fullof openworld games that managed this.
for example Guildwars. the have simply a portal that leads into the next level. now in my case this isnt the answere but i adapted the idea.

World Composition within World Composition.

example. one level that contains 4 levels, each of those contain the remaining levels to sustain a high quality map.

BUT… IS THAT POSSIBLE or does it even make sense?
or is there an other answere to my problem? maybe by making use of viewing distance and streaming distance?

so apparently these values from epicgames dont match current standart.

Simon Trembly was able to create landscapes with different values.

EPIC GAMES recommends a maximum of 1024 components what makes sense to me but having a tile size of maximum 256x256 just doesnt seam to fit. Simon Trembly created a landscape of 8km x 8km cut into 16 levels (4x4)
with a tile size of 2017x2017.

this is were im confused. are the numbers from EPIC GAMES out of date and if so whatr are the current ones we can use to create hightmaps in world machine?