I don't see the scale as much of an issue really - its a brand new setting for a start, its more Bravestarr/Firefly than standard "Old West" to be frank -...
Funny coincidence, I was drawn into the KS by the Outlaw minis, they reminded me a lot of Clone War era Bountyhunters and I decided to pledge.
I received now Lawmen, Outlaws and the "NOT" Firefly/Serenity crew. I am happy with them.
The old Deadland minaitures are of similar size, so the only mini line that is of the same "genre" is by accident compatible.
And as said they are not THAT big. Not like Spartans Distopian Legion giants.