You could do anything with the proper amount of fab work, and a lot of fab work is what you would need to do this.
The fenders on the XJ are extremely weak sheet metal, and wouldn't be able to hold the weight of the door. You would need to fab up new brackets that would extend to just behind the fender from the A pillar/inner fender area. The wrangler brackets would need to then bolt to this.
The metal would need to be reinforced on the door as well.
But, it would be a heck of a lot easier to just fix the XJ hinges.