The source of my confusion, has been the fact that {poS} and {leQ} are locatives, as for instance {bIng}, {Dung} etc.

Locatives aren't always to be placed second in a noun-noun construction ?

None of those are locatives. They describe locations, but they are not inherently locative as naDev, pa', vogh, and Dat are. Only those four words are known to be inherently locative.

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SuStel
http://trimboli.name