I just guess that the name are at one end of the phonetic scale with finland bein the other end (as in a country which is very phonetic in spelling). (what you see is what you et kind of. Even English itsself hasn't got phonetics as their strong point lol, no surprise seeing the spelling hasnt changed a lot in a couple of hundred years..., in fact English is even one of the only languages that doesn't even have phonetic vowels .lol
I'd be quite interested to see how Irish phonetics work to see the logic behind their spelling

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Anyway on topic, There aren't many names i have a particular dislikening to but if there is one then it is Kevin purely because it is overused in Germany especially by the bottom end income group. (such as the German equivalent to chavs) mostly with a very German surname .. (and apart from that is that german rather pronounce it Ke-win rather than kevin. (It even spawned a name cateory called Kevinism(or chantalism for the female version)
Considering the spelling there is actually a law in Germany that says that the spelling must be a standard/common spelling of the name , and not something they imagined.