I'm talking about pronunciation brah. But yeah I made a typo but my point's the same. X-Ray is pronounced with a leading vowel so simply it's preceded by "an", the other one is pronounced with a leading consonant "g" as in "gzy" so it is preceded by an "a". Typo fixed
European is pronounced with a hard "y" so it's preceded by an "a", as in "a young man". To me it's super simple. The other examples I showed are much harder to justify, you kind of just have to memorize those.
Even in pronunciation it's not gzylophone though, just zylophone. Don't even know how you'd pronounce "gzy" Like "guh-zy"?
Although while we're talking about "x" it seems like the most pointless letter in the alphabet. It could easily be removed and replaced with different letters which would produce the same sounds in the tiny number of words that it even appears in.
You need to remember that there are international pronunciation variants. It's subtle , but you'll see that that z is softer in the brittish version.
The american version has a harsher zai sound, which could sound like a "gzy" but with a very light g. While both are marked "zai" on google (for pronunciation), the american one sounds different. To go further, I'm Canadian. There is a regional difference here in how we pronounce things, even though we're lumped together with American English in most pronunciation samples.
"x" is a historical letter which comes from greek and allows words to be spelled (or spelt) similarly to other languages such as French, where the "X" in "xylophone" will really sound like a "gzy", much more than the american pronunciation in English.
If you replace it with another letter, you lose that similarity, etymological breadcrumb and the reason why it sounds different in American English as compared to British English.