Don't see how wiring in parallel would work really. Usually when your wiring like this your wiring the same cuts to get an even stable temp. I think they want one shelf at one temp and the rest at another.
Only way I see this happening is either with 2 controllers and 2 probes or playing with the temps and sacrificing exact temps for a in between temp read that will "satisfy" the snakes, but I really don't recommend this. Having two different cuts in parallel without exact reads and individual temp controllers is dangerous in my opinion. The Herpstat Pro I believe is capable of handling 4 controllers in one unit and has 4 probe slots, but if you don't want to use more than one thats where the problem lies. Better off either using 2 individual controllers on that thermostat or building another small rack for those indiviual temps you want and taking advantage of more rack space for that slot.
Hope that makes sense.