Who to ask a technical Hebrew/ Bible query?

There seems to be a popular idea that to be a trustworthy expert in any particular subfield of Torah one must also be a posek, or the converse, that the greatest poskim are also experts in all subfields of Torah.

R. Josh Waxman at Parsha Blog posts a responsum of R. Ezekiel Landau with translation. He notes that "[t]here are great quotes to be culled from this."

Indeed. Here is one:

והנה אני תמה על שבחרו לשלוח שאלות הללו לחכמים ולרבנים זיל קרי הוא שאלו לבעלי מקרא

And behold, I am astonished that he chose to send these halachic queries to Chachamim and Rabbanim! Go and read his query to experts on Scriptures. (translation is Josh's.)

See his post for the full text of the teshuva, which is found in the first section of נודע ביהודה, second responsum in אורח חיים.