The sides of the seat bottom is not leather, rather vinyl
Even if the bottoms are interchangeable, you risk damaging the passenger occupancy sensor if trying to swap bottoms.
IMHO, you're better off taking the driver side seat bottom off and taking it to an upholstery shop and have them replace the side bolster with leather so it lasts way longer.
For mine I applied several layers of leather/vinyl repair liquid using a texture pattern sheet therefore hiding the cracking and it has held up well for several years. My seats are black and it's hardly noticeable unless you're looking for the repair.