The important thing to understand is that Gerard, Sabine et al. are already doing the best they can do using the *present* wiki system. You can sort of hack yourself internationalizable field names by using templates like {{-noun-}} (you still have to redundantly copy them around), you can try to keep the data in a certain structure so it can be parsed by a script etc.
But these are *hacks*. They will break, they will be inflexible, they will be redundant, and they will not be properly supported by the software itself (try doing a search for a translation in a particular language, for example). UW tries to remedy this by adding structure where none previously existed and unifying the content in a single DB to reduce redundancies (without eliminating needed flexibility).
Best,
Erik