What you're seeing is Simple Seablock's standard Gleba generation (where the quartered layout is very much intentional) with a few extra plants on top of it. Presumably what's happening is Space Age Without Space is merging the terrain gen from all the different planets, and the Simple Seablock Gleba generation is mostly "winning" and overriding the rest. SS's terrain gen is intentionally quite "destructive" since the whole idea is to remove everything else from the map so I'm not surprised it doesn't play nicely when trying to combine things like that.
This is a case where we have 2 mods doing significant terrain generation overhauls in very different and incompatible directions, so ultimately the best approach might be for me to mark SAWS as an incompatible mod to avoid confusion.
If you're interested in a Nauvis-only playthrough, there's another discussion thread that just started around potentially adding compatibility for Space is Fake, which starts from a place that looks to be more compatible with Simple Seablock
https://mods.factorio.com/mod/SimpleSeablock/discussion/69fda72bba8fc3508249723b
