My guess is the second greatest good would be the best option. Taking into account that these are mortal beings and you don't know how long will these people live/be healthy, the best choice would be one that is not the least rewarding (first greatest good) neither the slowest to come.

Think of it as spending your life savings: you don't want to spend it all on your youth and be poor the rest of your life and you don't want to spend it all in your nineties either, when you'll be too old to enjoy it. The answer is somewhere in the middle.