Am I missing something here, or being too literal in reading this? The possessive in Russian ..."is termed archaic and/or colloquial?" Not according to Russian grammars I've read.
LOL, I read that in a (Penguin) Soviet-era grammar from 1961. Got any older?
My 1916 Russian grammar says the possessive is "sometimes used, especially in the popular language", but doesn't treat the -ov forms as non-productive. It also lists an -iy form as applying to a whole group, species, e.g. волчий. wolves', wolfish, of wolves, lupine.
NB I'm not saying that the genitive case forms are becoming obsolete in Russian, that is quite something else. If your name was Rodion, your reply would be "oтвет Родион
а".
And while it's possible to express possession in more than one word ("of",or "belonging to"), those formulae would be awkward at best in many languages. This wouldn't ever be called the reply of Rodney or the reply belonging to Rodney, but rather Rodney's.
In many Germanic languages: German, Dutch, Norwegian etc. this is happening as we speak, i.e. the language is going from a synthetic form (
Rodneys), now mostly reserved for writing, to an analytical form with a preposition (
von / van / til Rodney), which is very common in the oral language, and increasingly also in the written language. It never struck me untill now that English may be developing in exactly the opposite direction? Perhaps we tend to use pronouns to express this orally just as much prepositions:
Rodney seine Antwort/ zijn antwoord / sitt svar, i.e. "Rodney his answer".
In Romance languages this happened centuries ago, already in Vulgar Latin time. Classical Latin was a synthetic language just like Russian (thus
responsum Rodneii if we Romanized your nomen barbaricum to Rodneius :-). But in most modern Romance languages you express it analytically, with a preposition:
la réponse de Rodney. The odd exception is the isolated Romanian (which also has been in close contact with Slavic languages):
Maria, Regina României - Maria, Queen of Romania.