the tiling looks strange.
The tiling looks odd because there isn't any.

The engine doesn't use bitmap tiles, instead it paints the terrain by blending texture samples (grass/rock/sand etc) together according to a rule-set (height/slope etc). It means that most features need to be hand-painted but there's no tile repetition.
do you have some kind of sat map that underlies this detail map?
We can add a sat map underlay but at a resolution of 1 pixel per 10M square meters it doesn't have the desired effect. It just adds noise and minor colour variation.
Without sat-map underlay:

With sat-map underlay set to blend at 50%:
The benefits in low lying areas are quite promising.
Cheers