Yeah, it’s that bad. In English you have “friend” and “friends” for the noun and that modifiers are other words of the sentence, so you could use one key for friend and one key for friends. In Russian “friend” could be друг (friend), друга (of a friend), другу (to a friend), друга (action towards a friend), другом (with a friend), о друге (about a friend). All cases modify multiple nouns differently than singular nouns (6 variations of “friends”). Also all cases will modify singular noun of female-gender equivalent differently (there’s a different word for woman-friend). Also some phrases that can use word “friend“ in English require a completely different word in Russian For natural language flow - for example “add friend” could be directly translated “добавить друга”, but it doesn’t sound right this way (it’s like “add friend to something”) so we have to use equivalent of “establish friendship” or “become friends”.
This is just an example of two languages from same group (Indo-European) and how different they can be. If you consider Chinese, Tamil, Turkish, etc it becomes clear that it is impossible to reuse keys as shared classes in different places.