I don't think that that is the right question - if one was made well, then it would finance further ones - if it was done badly then it wouldn't matter which one they cocked up - "Lord of the Rings" survived the earlier Ralph Bakshi version.

In terms of what to start with, I would say start with "Men At Arms" - the character development is a bit more advanced, and movie viewers tend to need more spelled out for them than do readers - there is already the "prequel" precedent of Star wars to allow "Guards Guards" to be made later.