Tolien and other mythology

[Sicirus]

Has anyone ever read "Tolkien's Ring" by David Day?
It is quite interesting. I was reading chapter six dealing with similarities between Aragorn, Arthur, and Sigart. (though I honestly have no idea who Sigart is, so if you know can you tell me please)
All three were orphaned sons of great war heroes and heirs of a kindgom. All three were raised by foriegn fathers. All three wanted to marry very beautiful maidens but had to go through tough obstacles to win them over. Or in Aragorn's case win over Arwen's father.
Arthur had to win over Guinevere who unfortunatly betrayed him and becme a nun because of it. And Sigart's wife commets suicide.
As we all already know Arwen

marries Aragorn and dies a human death not following her father to gain immortality in the undying lands.

As well as all three had unbreakable swords. Well Arthur's sword breaks when he makes a stupid move on Sir Pallien. And Sigart and Aragorn both can be defeted by a magical foe.
Thats all I have learned so far. Just thought this would be interesting to you all for it was to me.
I have more linkeges to post later.