connect series of batteries in parallel?
If you're worried about a battery having an internal short, this would cause half of your batteries to die if one does have an internal short.

On the other hand, if you're just trying to keep them balanced better, then adding the green wires is a good idea. They turn your system from 4 separate 2S batteries into one 2S battery. This means that if one battery has less capacity than the others, the other three in parallel with it will help prevent it from seeing high over-voltage when charging and a negative voltage when discharging.