I thought this was a bodybuilding forum
I wouldn't limit it to there and seeing you could have posted it closer in depth in a deeper section but I will help as I can.
I think what they are saying is that isn't as important as other aspects of this lifestyle (or they are not genuinely concerned with it). But after a quick search of other outlets I found that a good rule is neck,arms and calves being relatively close. You can find more info if it is important to you fairly easy.
Not a bad rule but tell me how many great physiques have you seen even nowadays with an Arm:size ratio that looked proportionate by any means?
Toouch goes into the insertion point of your gastrocnemius and soleus. Bottom line either you will have large calves or not and its one of few muscle groups where can you improve them...yes, shaping and defining them can go a long ways but I honestly believe there is far superior chance for true growth on the Tricep/Biceps in comparison to the Anterior tib, gastroc, soleus, and perineal groups. I don't even know if you can get hypertrophy in the perineal a but maybe lol
In the end as far as proportion goes I do believe forearms and calves are a closer comparison and neck size would be dependent on too many factors. If you want to make them more proportionate go for it, but one won't be anywhere near the potential of the other. Again this is just my broscience