Legal documents have a strong authoritative tone by nature (and not only by virtue of their legality). I feel a translation should give the same feeling, using terms the reader will recognise as equally authoritative.
Which is why something like "The king has decreed that henceforth all issues be addressed to the minister" would be better than "The king says from now on, everyone has to ask the minister if they have a question." That is what I meant by tone.
Legal nuance is exactly what contracts are meant to convey, and this is often why we need lawyers (not just a native speaker) to interpret them, doubly so in translation where laws and conventions (like leasing and renting) may be different. Probably for this reason the word pairs you mentioned have survived in English. Did you ever consider they might be there to avoid translation as the wrong word into other languages which may not make a distinction otherwise?