I dont think their pronounciation is set in stone and universally applicable. A
German would pronounce the V in
Valkyrie, bur a fellow in New Zealand fould use a V sound instreas. A Fravhman would pronounce
Sapphira on the last syllable (SapphirAA), unlike a Greek (ZapphEEra) and unlike a Japanese (SapphiLLa) :)