10mm Sudan Fort - query on size

[Dazza]

Hi,
I have recently moved into the colonial era in 10mm, after having a large collection of 15mm.

I am using the supplement to Black Powder and was wondering what ground scale I should use for the fort base and what sort of height would not look out of place.  I am using 20x20 bases with 3 figures on each, with a frontage of 80mm.

I always want to make it too big and for some reason it tends to lean more towards 15mm

Any help would be greatly appreciated.

Cheers

Dazza