> You will end up with way too many conflicts unless you basically "lock" sections through either a software mechanism or agreement, because edits often touch or reorder many paragraphs. A copyediting/wording pass will typically touch every paragraph, for example, and these are more frequent in writing than refactoring or variable-renaming passes are in coding.

As stated above, Dropbox doesn't even try to merge files, but Git does, which is definitely an advantage (at the very least, it tells you where the conflicts are, which is far more reliable than trying to work out the conflicts by hand, or with a separate diffing tool).