Both single stage propane regs on the tank?

I just purchased a nice 120 gallon tank and it came with a single stage regulator on the tank. I also got a brand new second stage regulator with it. I am replacing a rented tank with a two stage reg on it. In anticipation of getting the same thing I had already plumbed some CSST to feed two cook stoves and one 150K BTU on demand water heater. The configuration is a 3/4" trunk that has one 1/2" teed to one stove about ten feet out and another 1/2" tee for the second stove about 20 feet out and then the 3/4" continues into the house for the water heater. I am certain this will handle the needed capacity as all three will be intermittent use. Both regulators are high capacity.
Here's my question.
Is it considered bad form or is there any structural or regulatory reason not to put both the single stage regulators in series together on the tank? (there is room under the cover) I haven't found much on it but I can't see how they know the distance between each other. I can always just go get a two stage but then I have to sell these shiny new singles. Thanks…