I am somehow bemused by the sixteen cases of the Russian. On the other hand, I thought that there were only six kinds of declension. Perhaps these two facts are not contradictory, but the problem is that I am not aware of the difference between case and declension. During my only Russian course, I was given some declension tables with 6+6 endings: six endings for nominative, genitive, dative, acusative, instrumental and prepositional, plus six from their plurals.
Can some (hopefully all) of the 16 cases in the aforementioned question be grouped, as to obey one of the six common declensions? If so, which cases obey which declension rules? If not, I'm afraid that one has to learn a 16+16 table.