Different havaras

They were likely influenced by the local languages that were spoken. I’ve heard from many people (including Rabbonim) that the Teimanim have the closest to the “true” havarah.

There are things to look at to try and see which are more correct than others. For example, look at the cholem pronunciation. Some pronounce it as “oh”, some (mostly in the yeshiva and chassidish world) use “oy”.

The Gra wrote that the cholem is a combination of a kamatz katan and a shuruk, and is formed with the lips. That would indicate the “oh” sound, as “oy” is formed with the tongue and the top of the mouth.

There are also numerous seforim which point out how to be makpid on pronunciation while saying Shema. They point out the words which end with a yud sound and begin with an “open” sound, such as “mitzvosai asher”, saying that one should pause so the yud sound doesn’t carry over and make “asher” sound like “yashar”. They also mention words which ends with a sound and the next word begins with the same sound, so that you have 2 distinct sounds, and not one which runs from one word to the next. They mention each instance, but do not mention the cholems such as v’lo yihyeh and b’ito yoresh. If they were pronounced as “oy”, these should be on the list of places to be careful!

R’ Henkin zt”l, in Eidus L’Yisrael, says that we should adopt the Sefardic pronunciation of the letters, but not the vowels. R’ Ovadia Yosef zt”l paskened that while one should hear Parshas Zachor in the havarah he/she usually uses in order to be yotzei, anyone can hear it with the Sefardic pronunciation and be yotzei, as it is the “correct” pronunciation.

As for other havaras, there is also the yekke havarah, the Ladino havarah, and I’m sure plenty of others.

Joseph, the so-called Chasidish havara split from the Litvish ,

It has do do with the region and nothing to do with “Chassidish or Litvish”. Lita is a country, not a way of life and there were many Chassidim there. There are many Chassidim such as Slonim, Stolin, and Lubavitch who speak with a so-called “Litvish havara” and there were many non-Chassidim in Poland and Hungary who spoke with a so-called “Chassidish havara”. Even today, if you go to Krakow you will hear the goyim there say “the Ramu”. The Gra in all likelihood said neither “oh” or “oi” but “ay” as the old Litvisher Yidden pronounced it. The local languages influenced all havaros and no one can claim one is more “correct” than the others are. R. Moishe Zt”l has a teshuva about being yoitze hearing other havaras and about saying anything out loud (shliach tzibur, baal koreh, aliya) according to the minhag hamakom. It is entirely possible that there were originally different havaras among the shevatim just as the Ariza”l says that each shevet had a separate nusach hatefila. You see a few places in nach and shas where various people had different ways to pronounce words.

Google “Gefilte Fish Line”

I heard that that the “s” sound for the saf is actually based on the Teimani pronunciation (a “th” sound) but in Europe they couldn’t pronounce the “th” sound (like old Europeans would say “sank you very much”).