I have a particular fondness for playing druids in AD&D 1E. Though, upon reading the Players Handbook, I must admit that I think Gary goes a bit off track in describing the Class.
On one hand, they are described as being True Neutral because concepts of Good and Evil are secondary, if even considered, matters. They follow Nature and thus believe in balance of all things. OK, I can see this, I am on board so far.
Then he turns around and says that regardless, druids are out to protect, revitalize and strengthen their charges. Mmm, this is starting to sound just a tad bit Good leaning now. Though, it obviously isn't exclusive to Good to take care of their own, it's pretty much a hallmark of Good to do so. Evil is just as likely to allow their own to suffer and be harmed if there is no immediate usefulness to them.
I can definitely see Druids as being Neutral in terms of being lawful or chaotic. At the same time, I can see Druids as being Lawful more than I can see them being Chaotic. I still see the Neutral being more the base of Druids because for druids, it's not all about the group and it's not all about the individual. For Druids (most of them anyway), It is what it is regardless of what a group of people/creatures think or what any individual thinks.
In the end though, I think when it comes to PC's, it should be left up to the Player. If they want to have a CG druid, perhaps it is because there is some sect or order of Druids that have identified something within Nature that shoves them to take on a Good or Evil position. Or being a part of a Druidic order or sect that demands one to be Lawful. Or maybe it's just recognition of Human or racial nature to aspire to be Neutral but still struggle with inner conflicts and in their heart they are still a bit Good or Evil or lawful or Chaotic.
So, in the end, I allow Druids to be what the Player desires them to be. Though I do require, for Clerics as well as Druids, a background to be written up for the PC. Something that gives some insight to their personality and life experience that would motivate them to be anything other than True Neutral.