I think Earth can be tied in, ONLY if it can be done in a plausible way, i.e. it's the far, far future, mankind has colonized other planets in our galaxy, and Eternia is one of those planets. But as for any of the MOTU characters being from Earth... I'm more iffy on that. Why does Marlena need to be from Earth? Or Adam? To me, it's enough to say that the humans of Eternia are descended from the original human colonists. Nothing more than that is really necessary, IMHO.

You're both wrong, though, in regards to
LOTR. If either of you had actually researched Tolkien and his work, you'd know that
Middle-earth IS Earth... thousands of years in the past! The name Middle-earth wasn't even created by Tolkien. It's a modern English transliteration of various ancient names for the Earth, from various cultures. In fact, it's the modern English equivalent of the Norse name for the Earth, Midgard. Of course, Tolkien was really into history and languages. As a linguist, he even based his invented languages on real languages from European cultures. If Elvish sounds familiar, it's because it's based on a real language. I think the end of the Third Age (the time period of
Lord of the Rings) is supposed to be roughly 6,000 years ago. Just like Robert E. Howard's Hyborean Age (the era in which Conan's adventures take place) is Howard's imaginary ancient Earth of about 12,000 years ago!
Now, of course, with
MOTU being Science Fantasy, you could always give it the ultimate Science Fantasy twist, which is that this story, seemingly set in a distant, forgotten past, is actually taking place in Earth's far FUTURE, thousands of years from now, when our present day is the past that mankind has forgotten!
Anyway, there's different ways to go with it, as long as it makes sense, and isn't as campy as one or more of the characters being astronauts from Earth some... 10 or 20 years from now, or something stupid like that, then I'll probably be okay with it... unless they foolishly do a rehash of the first movie, and have He-Man and company running around on modern day Earth. There's no reason to do that kind of low budget cheese AGAIN. It would surely put the final nail in this franchise's coffin!
