Yes, 6x4 means two powered axles.
In this case - In the back, close to one another, under the cargo platform.
An example:
For off road a 4x4 with single tires is better than either :)
Which configuration is better for a truck expected to drive on "not very good roads":
- 4x2 with double tires in back (rear wheel drive, of course)
- 6x4 with single tires in back (rear wheel drive, of course)
I am talking about 1935-45 timeframe.