That article does not seem to refute the claim that Perseus was born of a virgin. Rather it appears to support the myth.
By the way if you want to claim that some of the Roman Gods were not the product of a virgin birth then by the same standards Jesus's birth was not a virgin birth either.
Demigods may have been virgin born but not virgin conceived. Why is the Virgin Birth so important? | GotQuestions.org
The doctrine of the virgin birth is crucially important (Isaiah 7:14; Matthew 1:23; Luke 1:27, 34). First, let’s look at how Scripture describes the event. In response to Mary’s question, “How will this be?” (Luke 1:34), Gabriel says, “The Holy Spirit will come upon you, and the power of the Most High will overshadow you” (Luke 1:35). The angel encourages Joseph to not fear marrying Mary with these words: “What is conceived in her is from the Holy Spirit” (Matthew 1:20). Matthew states that the virgin “was found to be with child through the Holy Spirit” (Matthew 1:18). Galatians 4:4 also teaches the Virgin Birth: “God sent His Son, born of a woman.”
From these passages, it is certainly clear that Jesus’ birth was the result of the Holy Spirit working within Mary’s body. The immaterial (the Spirit) and the material (Mary’s womb) were both involved. Mary, of course, could not impregnate herself, and in that sense she was simply a “vessel.” Only God could perform the miracle of the Incarnation.