The size conundrum

hi there,

so I recently thrifted a pair of brown vintage Docs, I believe they are made from crazy horse leather, size 37 and I think they are too small for me. Because I thrifted them, I am unsure whether or not someone else broke them in before( the sole is in good shape though). Now, I already have another pair of size 37 Docs and they fit , they are snug, but they fit (which is why I hoped these would too). I also have an old pair of Docs, which I bought many years ago, in size 38 -- they are pretty worn out and destroyed, but they are way too big for me now (note: I did lose 10-15kg since I bought and wore them years ago). I'll try and break these in, but I am not sure at what point I should give up. Any advice is appreciated!