Probably not? Chrono Cross just had a stupidly large cast of playable characters, so it had more of an issue with that sort of thing than more constrained games did.
It's not the only PS1 era game with huge cast lists (sup suikoden), but it probably had other considerations to work with, too (being 3d, for one).
Yeah, I think it's just that they came up with the word-endings trick in the Japanese one to make the ~43 characters dialogue feel different, so the English localizer just had to come up with a trick that replicated how they did that. For the Japanese version it would totally have been because then they can reuse dialogue without taking up more space. It was a form of procedural generation basically. The English localizer just had to jump through more hoops to make the same idea work for English, since the Japanese verbs they used for this are a lot more regular, so easy to change the endings.
Text has always been an RPG bottleneck because it takes up a ton of bytes (many CRPGs up through the early 90s shipped with a big chunk of the text in a printed binder of "paragraphs" instead of on disk, for example), and Japanese-to-English translations get hit ultra-hard by it because of the differences between the two languages.
Japanese has a very large alphabet, while English has a very small one. However, Japanese words are often much more compact in terms of number of characters, which saves a lot of memory. So, as long as you have enough text to outweigh the much larger alphabet, the same amount of Japanese text takes up a lot less space than the English equivalent. The real reason that the original FF II, III, and V didn't make it to the US, for example, was that they didn't think enough people would buy the extra-expensive carts (storing all the text needed more memory, and a proper English translation would need even more - there's a newer fan translation of III that is too big to fit on most SNES carts) needed to justify the cost of translation. So it makes a lot of sense that anything that balloons the text requirements would tax even a CD-based title.
Yeah there are a few reasons you could make it *really* compact on a disc for Japanese.
You need about 140 characters for the Hiragana and Katakana, so say you allocate 0-155 to those, that fits all the normal letters plus some punctuation into one byte, but then you can say that if the machine reads a code of 156-255, the top 100 values, then it reads the next byte as well, combines the codes and interprets that as a Kanji, so you could fit in
25500 Kanji as well, which is way more than you'd ever need - or you could use those codes to be shorthand for longer Japanese words in general, since there's no way in hell you actually need 25000 Kanji in the game. So normal symbols take 1 byte and Kanji/long word take 2 bytes (the same space as just writing the English word "a" and a space - Japanese doesn't use spaces), and Kanji can express entire concepts in one symbol. Also note that Hiragana/Katakana are usually equivalent to two letters in English, so か is "ka", so you already got that down to half the data space for that syllable because of how Japanese works vs ASCII.
You can do similar things to compress English text however Japanese just lends itself to that sort of thing much more naturally.