Interesting topic: linguistic of weapons. From what I could understand, there is unlikely to be a direct connection between the Portugese Sangue and Sangkur: just phonetic resemblance.
Many words in many languages have uncanny phonetic resemblance to other, unrelated, words in other languages. It is inevitable, because there are only so many sounds we can construct.
Some of them become a butt of jokes, especially when the translation is "risky". I know several of those (some with unfortunate personal experience) and could quote them, but the good taste of some Forumites is likely to be offended
Then there are homophones: words that are spelled differently and have different meaning , but may have similar (or, more precisely, confusing for the non-native speakers) pronounciation. even more dangerous....
