It’s a nice analogy but Latin has tons of weird idioms and exceptions. Been a while since I did it, but

1)the locative vs the ablative, and the locative only existing for a few words

2)the irregular verbs such as sum, eo etc, irregular nouns such as deus, aqua etc, and there’s a bunch of irregular like adjectives and stuff that I don’t remember

3)indeclinable nouns that just don’t decline at all and are the same in all cases. I think the word for “morning” is like this but it’s been a very long time. There are a few words that work this way anyway.

4) Words like “castrum” which just mean something totally different in the plural to the singular. “Castrum” means a fort, but the plural “castra” doesn’t mean many forts, it means a (singular) military camp.

5) Words like “Saturnalia” (festivals of Saturn) which only exist in the plural. As far as I know you can’t say one festival of Saturn in latin.