OK, so the question I raise is:
Is it permissible by RAW to purchase a TL-Barbed Strangler for a warrior?
Here are the relevant language:
Codex Tyranids pg 37: "Each warrior within that brood must then also choose two weapon-symbiotes at the cost listed, and no more...Warriors with two ranged weapon-symbiotes may only fire one per turn...Only one Tyranid Warrior per brood may take a barbed strangler or venom cannon."
Tyranid FAQ: "A Tyranid carrying two of the same ranged weapon counts them as a single twin-linked weapon". So per the FAQ two BS become one TL-BS.
One could point out that a Fex is able to purchase two
TL deathspitters or two
BS (which would then become 1
TL BS per the
FAQ) and thus a warrior shouldn't be able purchase a
TL BS, but that is not
RAW 
.