"Leetah was first repelled by Cutter until she saw aspects of Cutters personality and named it "Tam". "
But Leetah didn't give a name to Cutter's soul...he was 'Tam' from birth. His parents knew it, and Skywise knew it too (in one of the childhood issues, he clearly calls Cutter 'Tam' long before their recognition.) Wolfrider soulnames appear to be only half a name - I'm sure there was something about this in the BOTC novels. Because they are not full elf they don't have a full elf name, which implies that other elves DO have a name for who they really are, they just don't keep it secret and so therefore, for them, it is not a 'soulname' because it doesn't give anyone power over them.