yep. this is because of writing in japanese is confusing.One difficult one is Suisin because of spelling. Suisin should be 'Suishin' with a 'shhh'
you can't write the name suisin in japanese, it's spelled suishin in japanese. and should be pronounced as such.
like the way mazda is spelled in japanese. it's spelled as matsuda, not mazda.
"tsu" and "zu" can be interchangeable sometimes in pronounciation, sometimes it's regional (i think) on how it's pronounced.
the japanese kept the name mazda in romaji (what they call roman writing or western writing) coz it's easier for westerners to pronounce mazda than matsuda.
again the "u" in matsuda is silent, which is why sounds like mazda or matsda when pronounced.