Ok some of element of 4 tails maybe inspired from DB like the name Rōshi and the design of 4 tails which stated in naruto wiki.
"The Sun Wukong also known as the Monkey King is a main character in the classical Chinese epic novel Journey to the West."
"The origin of Sun Wukong is considered by some American, Chinese, and Indian scholars to be influenced by both the Hindu deity Hanuman from the Ramayana and elements of Chinese folklore."
"When Toriyama created Dragon Ball, he was inspired by Chinese author Wu Cheng'en's 16th century classic novel Journey to the West. The name Goku is the Japanese version of 孫悟空 (Sun Wukong), the central character of the novel"
The reason kishi use Son Goku for 4 tails name is because kishi is from Japan and Japaneses pronounce Sun Wukong as Son Gokū. If kishi is Korean then he would use Son Oh Gong for 4 tails which is Korean pronunciation for Sun Wukong.
hypothetically say if kishi use Son Oh Gong would u say he copy the name from DB too?
And for the number four, i couldn't find the significant with the fourth tailed beast in Naruto and the dragon ball that have 4 stars in it in DB..
The closest fact i get for the significant of Sun Wu Kong (Son Goku) with number 4 is Sun Wu kong is a character name in Journey to the West which is one of the Four Great Classical Novels of Chinese literature. (That's my guess)
And for addition..
"When Naruto meets him within Rōshi, he is sealed to a giant stone. This reflects the mountain under which Sun Wukong was sealed in Journey to the West."
"Handsome Monkey King and Great Sage Equalling Heaven are both titles Sun Wukong from the Journey to the West bears."
"The Water Screen Cave (Suirendō) is the cave where Sun Wukong was born on the Mountain of Flowers and Fruit."
and if u ask me why kishi still want to use the same name as in DB character. well.. ask akira why he use the same name as Journey To The West charatacter novel.