Optimal Shoulder fit on a lightly padded/ unstructured jacket vs more structured jacket?

Hi,

I recently bought a Brooks Brothers Fitzgerald, which has a narrower shoulder width than my usual jackets.
However, this jacket also happens to have more minimal padding than my other jackets.
I am very surprised that it still fits me as well.

My question is, do our parameters for what is acceptable in terms of shoulder fit change, depending on how structured/unstructured the shoulder is?
Is there more leeway?

I've included a picture of me in the jacket, if anyone could take a look and critique, would be appreciated.
BTW, suit has not been tailored, so yes the sleeves are too short etc.



Feel free to discuss. Apologies if this was better posted in the "Ask a Question" thread.

Thanks.

Claghorn, thanks.

vinnymac and Nicola,

my friend decided to take my picture while sitting down, which is why I look so tall