One can run 10/3 romex for 220 single phase to a location, and run with it a 12g. green ground with it. Perhaps not 'according to Hoyle' but at the business end one can 'split' into 2 - 110 circuits and still have the 'safety' mechanical ground....
Label what you've did/done....at each end.....
It's not nice to 'leave mousetraps' like that, and keep your amp loads balanced.
Cooking one side generally takes the other with it...just to make the point....;)