I always tell people that the Townasty wheels are designed to run with the stock 16" steel wheel on the inside for clearance reasons.
The way I look at it if you put 22s on the inside you are adding nearly 2" to the overall track width, kind of defeating the purpose of buying Townasty wheels in my opinion.
However if you want all 4 wheels in the back with the Townasty option they are available that way also.