How would you translate Zuchowaty?
I’ll say your translation as the Fifth “Dare-Devil” is damn good, no need to improve it. So the name would be; Fifth Infantry Regiment of the Józef Piłsudski Legions - Wilno, the “Dare-Devils”.
Does English have any such descriptives right in the actual name?
Sure they do, lots did and still do. For instance;
In US 1st Armored Division 1st Brigade Special Troops Battalion, is known as the "Black Knights" or 1st Armored Division 1st Battalion, 36th Infantry Regiment is known as the "Spartans".
Similarly British, besides the common name like; the Sussex regiment of foot, - 1st Infantry Division 3rd Infantry Brigade 2nd Battalion was known as “The Sherwood Foresters”, I believe and 3rd Battalion, Royal Regiment of Scotland was known as “the Black Watch”.
Here's a bit more about 5 Pułk Piechoty Legionów im. Józefa Piłsudskiego in Polish
nasz-czas.lt/508/czas.html