Tsunade’s full name is Senju Tsunade. . . The following is from the encyclopedia,,
Name: Tsunade Hime (Note: Tsunade's surname is officially recognized. Tsunade's grandmother is a Jinchūriki of the Uzumaki clan, but Tsunade's father and younger brother both have the surname Chi Hand, and Tsunade's mother is not from the Uzumaki clan. Many people speculate that Tsunade and Naruto have the same surname. Naruto does not take his father's surname because he wants to hide that he is Namikaze Minato's son to avoid unnecessary trouble)
The reason for calling him Tsuna is because it is his name instead of his surname. In Japan, people usually call him by their first names, just like Tsubasa also calls her Princess Sakura. .
As for Naruto, because his wife of the first Hokage is from the Senju clan, and Naruto’s mother is also a distant relative, I think Naruto is more because he inherited the will of fire. Well, and isn’t there a whirlpool on the Konoha logo, which proves that the Uzumaki clan and the Senju clan are related to Itachi,,,