No, no 9" will be stronger than a 1-ton axle. A one-ton axle is a full-floating axle, which means the axle shafts float inside of the load-bearing spindles and do not carry weight. A real truck axle is full-floating. Any semi-floating axle loads the weight onto the axle shaft. It uses much smaller bearings, there is only one bearing, and it subjects the axle shaft to a bending force while it is also transmitting power.
When Chrysler installed a Dana 60 in their Hemi cars, it was a semi-float Dana 60. What they were after was the ring gear and shaft twisting strength, not load bearing strength. My van had a Dana 60 as well, but it is not the same axle--it is full-floating with 1.5" shafts, but the weight is carried on much larger spindle bearings through which the shafts pass.
So, no, you aren't going to match a one-ton axle with a Ford 9", but you can make a 9" strong enough for any amount of power that a Ranger can put to the road. Just don't set a cube of bricks in the bed.