Hi! Today I received a peacoat in two sizes, which one fits me best in your opinion? Right one is one size bigger. As you can see I'm wearing a shirt and a thin wool crew neck beneath. I don't intend to wear anything bulkier beneath. I think sleeve length is better in the smaller fit otherwise they seem and feel pretty similar in my opinion. Also what are the common buttoning rules? I button both top buttons and the middle one and leave the bottom unbuttoned.