Ah, a good choice. I used that one to do the Ferraris Style a few years ago. I've moved onto other apps these days, but I still use Krita from time to time to touch up seamless tiles that didn't quite go the way I wanted them to in other apps.

Looking good so far.

What software are you using?

It will be interesting to see where you go with this.

And yes - Jonathan Roberts provided the artwork for both these styles. His website is called Fantastic Maps if you are curious.

On the second question you can add a Color Key sheet effect to the sheet the grassland is on and cut holes in the grassland using polygons of the Knock Out Color (Default magenta) where you want the holes to be. Make sure this effect is top of the list, so move it above any Edge Fade, Inner you probably have on that sheet.

Relyt is correct. There is no Walls, Dyke fill, but there is a Walls, Dyke drawing tool.

The tool draws 2 polygons on two sheets called WALLS DIKE Backing, and WALLS DIKE that don't exist in the template. One of these is drawn in purple and the other in a CD3 fill called CD3B_Grass Bright 1

Given the lack of the correct sheets in the template, and the location of the fill, at a guess this drawing tool has been included in the style template either by mistake, or as a much later decision. At any rate, it looks like it's supposed to draw a dyke in a grass texture over a grass texture with a bevel effect, making the purple backing sheet necessary to prevent transparency acne. You could get it to work in this style with some fiddling around - set the fill on the Outline Properties to be one of the native grass fills, use the tool, put the 2 new sheets in the correct order in the sheets list and add a bevel effect to the WALLS DIKE sheet.