The pronunciation of "leher" seems off. Should be more like "lay-heir"
Usually, you have only one neck. It is therefore wrong to put them plural, unless you are speaking of a medusa
Yes elsewhere the body part is not pluralized when the number of people are seen to be multiple. They can't share the single body part. This seems inconsistent.
Their, they,them means more than one person therefore they have necks( more than one)
The point is the (possibly) unnecessary reduplication; you wouldn't say "tiga leher-leher", so why say "leher-leher mereka"?
I meant a hydra not a medusa