If I create a new version of full translation, thouse methods are good.
But if I have found some errors or mistakes into one or two phrases in translation, uploading the full package is too long and hard process for several user to suggest only my variant of one-tow phrases. And it is too hard to synchronize two different files, when, for example, one part translated better in first file, another - in second. In modern translations systems you can register via web, find the wrong phrase, suggest you translation and community (or moderators) can apply or decline it, or users can vote for your variant of translation.