Exactly how copyrightable poses and such are is a grey area because there's no legal ruling. If you use MS Word to create a thesis on Poser copyright law, that document is copyrighted by you even though you used only 26 different letters and probably 3 to 4 different punctuation marks. I couldn't grab your document, change a few words, then claim it was my own creation. On the other hand, I could write my own thesis on Poser copyright law and although it would be the same topic and contain much the same terminology as yours, each of us would have our own copyrighted work. As for arguing on length determining how copyrightable something is, there's a problem with that: You can't copyright a word. You can copyright a poem. How many words does it take to make a poem? Regardless of legality, ethically it's not nice to take someone else's work, make a few changes, then call it your own without the original creator's permission.