But if huge hits like Twilight, Hunger Games or Maze Runner were called 'The Eagle Soaring High Above the Castle' would they be as big. Would they have even been published?
Published? Yes. With that title? No.
The content may be the same, but - shallow as it seems - packaging has a considerable impact on sales. They say you can't judge a book by its cover, but consumers can and do. Publishers (and agents, and most authors) want as many sales as possible. So they have marketing teams whose job is coming up with attractive packaging to get their book into the hands of as many readers as possible... or, rather, as many readers as will likely enjoy it as possible, as you wouldn't market an erotic romance with the same cover style and title as you would, say, an urban fantasy parody or a brooding literary work. Part of that is coming up with a title that'll catch a potential reader's eye.
It's sometimes interesting to look at how titles translate in different countries and languages. What strikes us as silly or completely mismatched likely makes sense to a native of that culture. Even the subtle differences between America and Britain make for different titles. For instance, Naomi Novik's alt-history fantasy with dragons in the Napoleonic Wars was titled "Temeraire" in England, where the battleship
Temeraire (for which the lead dragon is named) is still fairly well known, and "His Majesty's Dragon" in America, where we generally don't know about old ships in foreign wars but we do know that royalty often evokes elder-day England. And, of course, Harry Potter sought a "Sorcerer's Stone" in the States, where it was believed that the audience wouldn't be familiar with the alchemical Holy Grail of the "Philosopher's Stone," which he looked for in England.