I honestly think that these vehicles do look like they are supposed to be for separate reaces. The Humvee certainly doesn't mix with the others, nor does the bubble walker. The trike with tracks could, feasibly be from the same army as the Thundercats moving base, but the base would need some adjustment.
I personally think these sketches aren't too bad, but could produce some very nice vehicles. I'm just worried that they will be manned by Space Orks and Space Elves. I kind of like the idea of the Space Dwarves, and since they aren't technically a GW range anymore I see no problem with them being made.