Both locations have their benefits but I think the right camera in the Green Location is the superior choice.
The Blue Location affords you greater facial detail for someone looking over or climbing over the fence/gate, ergo more likely to be able to identify the individual to the police should the need ever arise.
The Green Location affords you a view of your window in addition to the gate/fence. Having camera coverage of all entry points to the home is certainly worthwhile and beneficial.
As others have noted extensively on this site varifocal cameras are worth the slight increase in price as they afford the greatest flexibility for installation. A varifocal camera at the Green Location would give you the greatest number of options for installation. You could opt to have it at a lower zoom and thus a wider overview of the area including the window or set it to a higher zoom level to achieve the same result as putting a fixed camera at the Blue Location. If you don't know varifocal cameras are not meant to be zoomed in or out during regular use, instead they are meant to be zoomed to the appropriate level for the install site and thereafter treated as a fixed camera. While you can change the zoom on a varifocal camera anytime, and often electronically via the camera web interface, changing the zoom is a slow process and so not recommended to do on the fly.
You could certainly install a camera at the Green Location above the interior ceiling line as you desire, the Green Location being further from the gate/fence will make the increased height and angle of the camera negligible for capturing faces.
Ideally the camera should have everything in frame you wish to monitor and nothing you don't. It is nearly impossible to have a truly perfect frame like that, but trying to minimize the amount of irrelevant in the frame is best. For example the sample photo of your Green Location shows a significant amount of your exterior wall between the camera and the window, this would be the kind of irrelevant footage you would want to avoid when installing the camera permanently.
These 3 varifocal Dahua are well liked on this site and would be worth considering in my opinion:
5231 Turret
5231 Bullet
8232 Turret
Hope this helps
(edit=changed a word because I used the wrong homonym)