In my opinion there are emerging/emerged technological solutions to both the reusability and localization paradoxes. Although it may seem amusing, copy and paste enables reuse on the most granular level, and automatic translation shatters language localization.
Remixers do this on a larger level but require much less expertise and time for the rebuilders. As with automatic translation, the results are not perfect but often more than useful and can be polished with comparatively little effort against starting from scratch.
This is all doable as we know from our interactions with such programs as are used to fill out tax forms. Constant reminders of the rules from the software may be annoying but in the end are useful. Hints about where to find more information also.
This does not take away from the fact that it always helps to know somebody in accounting but that a great deal of the work may be supported by building better tools and then using the tools to build content