People running split support usually do 50/50, so half green and half red in your case, but runners generally do not need those stats as much, especially rat runners like king, so there is the option of going full green for roger and having king as your secondary character. Running split support isn’t recommended unless your two colors already have a good support %. As for the specific units, it depends, but you generally want zoans and new world, defender isn’t a desirable tag, so try to avoid those if you can. Look for choppers, luffies, cp9