And you are ignoring every argument that doesn't specifically agree with you. Do the math.
There are more children with heterosexual couples, correct? Ergo, there are more children in danger. You yourself wrote "1/3 of the crimes." By your own words, that leaves 2/3 of the crimes. It doesn't matter who is more inclined, which you have still not proven, there are more children being hurt in heterosexual relationships. I ignored nothing...you are assuming facts not yet in evidence. We live in a society where people are innocent until proven guilty, and yet you are making a rash generalization. It is that same type of generalization that Abraham Lincoln argued with Stephen Douglas prior to the Civil War.
Curiously, no contemporary source and no archaeological evidence support this widespread assumption.
As for the evidence on the Spartans, The evidence is there in the literature of the time. While it is not explicit, there are strong suggestions, even in the Iliad and Odyssey, but also works from the early Greek playwrights, and some historians. The biggest problem here is that 90% of the historic record was destroyed when the Library at Alexandria burned to the ground.
Research the concept of Eros, as it refers to the ancient Greeks. I suggest doing this at the library and not on the Internet, or you will be besieged with images you don't want to see. The concept was to create strong bonds between warriors. Like it or not, Eros is a masculine love. As for the archaeological proof, I have seen pots and urns from the Lakedaemon region that shows older men presenting young boys with flowers. There are more images such as this than there are showing Men present similar gifts to women. Go to any historical or art museum, including the Metropolitan in New York, The Art Institute and the Field Museum in Chicago, the Smithsonian in Washington, and you will see a tremendous amount of evidence.
Even scholarly works by ancient Persians make note of this. Darius and his son Xerxes, both kings of ancient Persia invaded Greece (remember the battle of Marathon), and what few historic records of the time still exist, make note of the Greek practices.
Many modern scholars tend to gloss over this, I would guess, because of cultural bias. But we cannot judge an ancient culture by our standards, only by their own.
I don't know why the author you cite fails to take into account all that evidence, but it is there. Read the following: Early Sparta, by G.L. Huxley Lives of the Noble Greeks and Romans, by Plutarch Ancient Greek Houses, by B.C. Rider Daily life in Ancient Greece by R. Flaciere The Histories, by Herodotos The Cambridge Ancient History, Vol. III What Happened in History, by V.G. Childe Phallos: A symbol and its History in the Male World, by Th. Vangaard The Pelican history of Greece, by V.G. Childe The Early Ionians, by G.L. Huxley Oxford Companion to Classical Literature,
All of these prove my point. I do little research on the Internet because the each site tends to bear the bias of its creator. Anyone can produce a website that says anything they want. There is no scholarship involved on many of these sites, only vanity. I do most of my research at the Library. I am blessed with access to three outstanding college libraries within a one-hour drive of my house.
The Spartans were a subset of the Greeks, you did not cite any evidence of the Spartans embracing homosexuality as the Athenians did.