If I'm playing KoW and supplying both armies, then the physical unit sizes are really up to me.
The "stock" KoW sizes are a bit inconvenient for me since the smaller units use "odd" divisions of 20mm bases for total unit width. For example, 5 x 20mm (100mm total) wide for troops & regiments. Hordes are ok for me as they are 200mm wide. The basing plan I've been working with for other games uses 40mmx40mm bases. SO I've got to add an inconvenient filler or some similar solution.
But for either trying to adapt it for a solo game or hosting a game where I supply both armies, I can go 80mm wide for troops & regiments, and 160 wide for hordes. My basic "building block" is 4x(40mmx40mm) so my basic unit is = 2x troops = 1x regiment = 0.5 horde. Works well!