I’m not sure how specific a “this” you mean, but other languages modify adjectives by noun gender, e.g. masculine beau vs. feminine belle in French, and other languages sometimes have categories that are determined by suffixes, e.g. -chen signifying neuter diminutives such as Mädchen in German.
Since I’m not a native speaker of Irish, I can’t say how “natural” those rules are, but I’d imagine it would be similar to e.g. putting adjectives of size before adjectives of color in English — i.e. it’s “natural” for native speakers of English to refer to “a big blue ball” rather than “a blue big ball”, even though the latter phrase is also grammatically correct.
Good example, and yeah that makes sense. It was actually the genitive rules that got me thinking about this. It was actually trying to get my head around the lessons on the genitive that got me thinking about this. As in 'capall' is the nominative singular, but nominative genitive is 'capaill', but these essentially get reversed in the plural (but with a h in the singular genitive and a g in the plural genitive). Obviously, it seems random to somebody like me, but probably makes perfect sense to a Gaeilgoir. But I'm aware that I'm coming at the language from a point where I didn't understand any of this at school.