Well, we don't really. One set of Tolkien's notes gives them the names you used but the accuracy of those is debated by the community, especially as elsehwere he keeps saying they have no names and elsewhere again gave them entirely different names.
That's the prolbem with Unfinished Tales; Tolkien kept changing his mind with his notes and they are often contraductory and not necessarily authoritative.
Originally posted by Darth Ninja
Gandalf is the strongest!? 😆 Smaug would've fried Gandalf with his fire breath. . . then eaten him. 😂