Roof pitch question....

I'm currently laying out the footing for a 30 x 30 greenhouse with a north wall and partial east/west walls in a hill.  I'm a few days away from "finalizing" a list and getting everything on order, but I am arguing with myself regarding the roof pitch....

I'm in Virginia -- 38.9 N Latitude.  I am arguing with myself over a short south wall with a 45 degree angle with glazing on the roof, or a taller south wall with a 22.5 degree angle roof.  

Steep pitch, shorter front wall:
http://sundancesupply.com/RoundMtn.html

Less Steep, taller front wall:
http://www.ceresgs.com/wp-content/uploads/2016/07/Leadville-Greenhouse.jpg
http://helios.pomfretschool.org/solar-greenhouse.html
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I read an article once that even though the roof angle should be latitude plus 10 or 20 depending on what article you read, but I've also read that the light loss at a smaller 6/12 roof angle is negligible.  I also don't want to burn anything in the summer if I decide to grow in the greenhouse all year round.

Thank you in advance for any suggestions;

I think I found my answer on another thread and reference to another blog.  https://vergepermaculture.ca/2013/07/11/greenhouse-update/

Lucas, I am interested in what the verdict is for the pitch of the greenhouse roof. I searched but could not find a solid answer at the link you listed.

In the write up, it states "The future greenhouse will have a simple shed-style roof slanting to the south but with a much lower angle to allow for a knee wall which will push the ventilation wall further up.".  I have chosen a 5/12 pitch for my greenhouse, but Ceres greenhouse states even a 3/12 is fine if you have a front wall with windows.