Bob,
In my opinion 300.3(B)(3)would permit this installtion if the raceways were nonferous. Note that you would have to comply with 300.20(B) where the conductors enter the panel. If these are ferous raceways, then the installation is a code violation and will fail very quickly when any load is applied.
Pierre,
I see nothing in 300.3(B)(3) that says you can't use the section for parallel installations.
Don
